entity framework - System.AccessViolationException due a System.Data.Objects.ObjectQuery -

from time time i'm getting exception of type system.accessviolationexception in w3wp.exe crash app.

the stack of exception (got event viewer):

log name:      application source:        .net runtime date:          05-04-2013 00:00:27 event id:      1026 task category: none level:         error keywords:      classic user:          n/a computer:      myserver description: application: w3wp.exe framework version: v4.0.30319 description: process terminated due unhandled exception. exception info: system.accessviolationexception stack:    @ system.collections.generic.list`1[[system.__canon, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]]..ctor()    @ system.data.common.internal.materialization.coordinatorscratchpad..ctor(system.type)    @ system.data.common.internal.materialization.translator.processcollectioncolumnmap(system.data.query.internaltrees.collectioncolumnmap, system.data.common.internal.materialization.translatorarg, system.data.query.internaltrees.columnmap, system.object)    @ system.data.common.internal.materialization.translator.visit(system.data.query.internaltrees.simplecollectioncolumnmap, system.data.common.internal.materialization.translatorarg)    @ system.data.query.internaltrees.simplecollectioncolumnmap.accept[[system.__canon, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089],[system.data.common.internal.materialization.translatorarg, system.data.entity, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]](system.data.query.internaltrees.columnmapvisitorwithresults`2<system.__canon,system.data.common.internal.materialization.translatorarg>, system.data.common.internal.materialization.translatorarg)    @ system.data.common.internal.materialization.translator.translatecolumnmap[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]](system.data.common.querycache.querycachemanager, system.data.query.internaltrees.columnmap, system.data.metadata.edm.metadataworkspace, system.data.objects.internal.spanindex, system.data.objects.mergeoption, boolean)    @ system.data.common.internal.materialization.shaperfactory+typedshaperfactorycreator`1[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]].typedcreate(system.data.common.querycache.querycachemanager, system.data.query.internaltrees.columnmap, system.data.metadata.edm.metadataworkspace, system.data.objects.internal.spanindex, system.data.objects.mergeoption, boolean)    @ system.data.common.internal.materialization.shaperfactory.create(system.type, system.data.common.querycache.querycachemanager, system.data.query.internaltrees.columnmap, system.data.metadata.edm.metadataworkspace, system.data.objects.internal.spanindex, system.data.objects.mergeoption, boolean)    @ system.data.objects.internal.objectqueryexecutionplan.prepare(system.data.objects.objectcontext, system.data.common.commandtrees.dbquerycommandtree, system.type, system.data.objects.mergeoption, system.data.objects.span, system.collections.objectmodel.readonlycollection`1<system.collections.generic.keyvaluepair`2<system.data.objects.objectparameter,system.data.objects.elinq.queryparameterexpression>>)    @ system.data.objects.elinq.elinqquerystate.getexecutionplan(system.nullable`1<system.data.objects.mergeoption>)    @ system.data.objects.objectquery`1[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]].getresults(system.nullable`1<system.data.objects.mergeoption>)    @ system.data.objects.objectquery`1[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]].system.collections.generic.ienumerable<t>.getenumerator()    @ system.linq.enumerable.single[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]](system.collections.generic.ienumerable`1<boolean>)    @ system.data.objects.elinq.objectqueryprovider.<getelementfunction>b__3[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]](system.collections.generic.ienumerable`1<boolean>)    @ system.data.objects.elinq.objectqueryprovider.executesingle[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]](system.collections.generic.ienumerable`1<boolean>, system.linq.expressions.expression)    @ system.data.objects.elinq.objectqueryprovider.system.linq.iqueryprovider.execute[[system.boolean, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]](system.linq.expressions.expression)    @ system.linq.queryable.any[[system.__canon, mscorlib, version=4.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089]](system.linq.iqueryable`1<system.__canon>)    @ my.webservice.networkvalidation.validip(system.string)    @ my.webservice.sedeservice.islogged(my.database.sededata.user)    @ my.webservice.sede.islogged()    @ dynamicclass.syncinvokeislogged(system.object, system.object[], system.object[])    @ system.servicemodel.dispatcher.syncmethodinvoker.invoke(system.object, system.object[], system.object[] byref)    @ system.servicemodel.dispatcher.dispatchoperationruntime.invokebegin(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage5(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage41(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage4(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage31(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage3(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage2(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage11(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.immutabledispatchruntime.processmessage1(system.servicemodel.dispatcher.messagerpc byref)    @ system.servicemodel.dispatcher.messagerpc.process(boolean)    @ system.servicemodel.dispatcher.channelhandler.dispatchandreleasepump(system.servicemodel.channels.requestcontext, boolean, system.servicemodel.operationcontext)    @ system.servicemodel.dispatcher.channelhandler.handlerequest(system.servicemodel.channels.requestcontext, system.servicemodel.operationcontext)    @ system.servicemodel.dispatcher.channelhandler.asyncmessagepump(system.iasyncresult)    @ system.servicemodel.dispatcher.channelhandler.oncontinueasyncreceive(system.object)    @ system.runtime.iothreadscheduler+scheduledoverlapped.iocallback(uint32, uint32, system.threading.nativeoverlapped*)    @ system.runtime.fx+iocompletionthunk.unhandledexceptionframe(uint32, uint32, system.threading.nativeoverlapped*)    @ system.threading._iocompletioncallback.performiocompletioncallback(uint32, uint32, system.threading.nativeoverlapped*) 

the code of function validip(string ip) (last function call before exception):

try {                     using(var db = new accessentities())     {         var ret = db.accesscontrol.where(xx => xx.ip == ip && xx.isvalid).any();                             return ret;     } } catch (exception ee) {                     return false; } 

does have idea why happening ? call function every 1h , times times give exception, last time took 2 days , half happen, interesting thing i'm doing try/catch shouldn't able catch exception , prevent w3wp.exe crash ?

thanks in advance, rui

looks bug in clr or iis host asp.net (or broken installation - non-matching components etc.). have tried moving .net framework 4.5? bug might have been fixed in newer release. consider reporting bug microsoft - afraid there might not easy fix this.