Strange Error

I have the C# web application running on 2 servers - dev and prod. Dev
runs Win2K and the prod runs Win 2K3.
I noticed some strange behavior on the 2k3 machine. When I copy over
all the required files from the 2k server to the 2k3 server, the
application works fine.
SOMETIMES, when I make a small change to .aspx or .ascx files on prod,
with NO changes to the C# code, I get a strange error. The same changes
on the dev instance do not cause any damage. When I say changes, I mean
small things like adding a <p> tag to the HTML in the aspx or ascx
pages.
The error is as follows:
Server Error in "/" Application
Cannot execute a program. The command being executed was
"C:\windows\microsoft.net\framework\v1.1.4322\csc.exe" /noconfig @dotnet.itags.org.
C:\windows\microsoft.net\framework\v1.1.4322\Temporary ASP.NET
Files\root\.....
To recover from the error the admin has to restart the application pool
in IIS6.
Any ideas'BTW: the problem seems to have gone away after installing SP1 for the
.NET Framework
Spoke to soon.. I am able to reproduce the error again.
I simply modify some HTML and the error is reproduced.