Intermittent 404 errors on local .NET sites using UNC Paths as root

Question

I'm running into intermittent 404 errors on local .NET websites configured in IIS 7.5 to use a UNC path as their root folder. The site will work for awhile, and then I'll start getting 404 errors that can only be (temporarily) resolved by rebooting the machine. It seems to be a .NET issue, as I can hit simple HTML pages site without a problem. I also am getting these 2 errors in the Event Viewer for each 404 error response:

Log Name:      Application
Source:        .NET Runtime
Date:          1/5/2011 1:47:14 PM
Event ID:      1023
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      XXXXXX
Description:
.NET Runtime version 2.0.50727.4952 - Fatal Execution Engine Error (744D851A) (80131506)

Log Name:      Application
Source:        Application Error
Date:          1/5/2011 1:47:14 PM
Event ID:      1000
Task Category: (100)
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      XXXXXXXXXXX
Description:
Faulting application name: w3wp.exe, version: 7.5.7600.16385, time stamp: 0x4a5bcd2b
Faulting module name: mscorwks.dll, version: 2.0.50727.4952, time stamp: 0x4bebd49a
Exception code: 0xc0000005
Fault offset: 0x00074be5
Faulting process id: 0x%9
Faulting application start time: 0x%10
Faulting application path: %11
Faulting module path: %12
Report Id: %13

Anyone run into this issue before? Seems like a .NET bug...

Answer 1

There's a hotfix that might resolve this issue:

HOTFIX: A .NET Framework 2.0 application that runs under a user account context when no user profile is associated with the user account context may crash, or you may receive an access violation error message