w3wp.exe crash (rewrite.dll) IIS 7.5

I'm experiencing several crashes in the last days on our production server and I can't figure out how to fix this issue. The server hosts an ecommerce application, written in classic ASP, that runs under IIS 7.5 + MSSQL. Approximately one time a day, since Monday, the w3wp.exe process crashes due to an access violation in module rewrite.dll. No updates recently installed, no patches to the application code, apparently nothing has changed.

Has Anyone had similar experience and can refer me to a solution? Thanks in advance, here is the Crash Hang Analysis report from debug diag.

Type of Analysis Performed   Crash Analysis     
Machine Name     
Operating System   Windows Server 2008 R2 Service Pack 1     
Number Of Processors        
Process ID   456     
Process Image   C:\Windows\SysWOW64\inetsrv\w3wp.exe     
System Up-Time   7 day(s) 02:04:17     
Process Up-Time   6 day(s) 23:09:21 
Thread 10 - System ID 5640

Thread 10 - System ID 5640

**Full Call Stack** 

Function

rewrite!RegisterModule+38b86
rewrite!RegisterModule+38fd3
rewrite!RegisterModule+3855f
rewrite!RegisterModule+214d7
rewrite!RegisterModule+1ed78
rewrite!RegisterModule+1c2fc
rewrite!RegisterModule+3e63
rewrite!RegisterModule+5eb
iiscore!NOTIFICATION_CONTEXT::RequestDoWork+d5
iiscore!NOTIFICATION_CONTEXT::CallModulesInternal+305
iiscore!NOTIFICATION_CONTEXT::CallModules+28
iiscore!W3_CONTEXT::DoStateRequestStart+63
iiscore!W3_CONTEXT::DoWork+8d
iiscore!W3_MAIN_CONTEXT::StartNotificationLoop+49
iiscore!W3_MAIN_CONTEXT::OnNewRequest+47
w3dt!UL_NATIVE_REQUEST::DoStateProcess+26
w3dt!UL_NATIVE_REQUEST::DoWork+60
w3dt!OverlappedCompletionRoutine+1a
w3tp!THREAD_POOL_DATA::ThreadPoolThread+89
w3tp!THREAD_POOL_DATA::ThreadPoolThread+24
w3tp!THREAD_MANAGER::ThreadManagerThread+39
kernel32!BaseThreadInitThunk+e
ntdll!__RtlUserThreadStart+70
ntdll!_RtlUserThreadStart+1b


Exception Information

REWRITE!REGISTERMODULE+38B86WARNING - DebugDiag was not able to locate debug
symbols for rewrite.dll, so the information below may be incomplete.

In WER4CBC.tmp.mdmp the assembly instruction at rewrite!RegisterModule+38b86 in 
C:\Windows\System32\inetsrv\rewrite.dll from Microsoft Corporation has caused 
an access violation exception (0xC0000005) when trying to read from memory 
location 0x7256665a on thread 10



Image Name: C: \Windows\System32\inetsrv\rewrite.dll
Base address: 0x00905a4d
Checksum: 0x00000000
COM DLL: False
ISAPIExtension: False
ISAPIFilter: False
Managed DLL: False
VB DLL: False
Loaded Image Name: rewrite.dll
Mapped Image Name: C:\Windows\System32\inetsrv\rewrite.dll
Module name: rewrite
Single Threaded: False
Module Size: 316,00 KBytes
Symbol File Name: rewrite.dll
Symbol Type: Export
Time Stamp: Thu Jun 24 01:11:33 2010 
Comments: 
Company Name: Microsoft Corporation
File Description: URL Rewrite Module for IIS 7
File Version: 7.1.0871.0
Internal Name: rewrite
Legal Copyright: Copyright © 2010 Microsoft Corporation
Legal Trademarks: Microsoft® is a registered trademark of Microsoft Corporation.
Original filename: rewrite.dll
Private Build: Built by danielvl on SPIDER.
Product Name: Microsoft® IIS Extensions
Product Version: 7.1.0871.0
Special Build: &

Try installing the hotfix from http://support.microsoft.com/kb/2749660

The hotfix will update rewrite.dll to version 7.1.1678.0

Another potential cause of access violations is faulty RAM, so it may be worthwhile running a memory diagnostic tool such as MemTest.