New Post: Temporary directory

I've just deployed an WCF service application that uses MEF to a QA environment and an issue jumped up and bit us. The security context under which the application is running must have read/write access to C:\windows\temp or strange things happen. The application loads, but when I try to access a custom section in my web.config, ConfigurationManager.GetSection returns a null. Through trace output, I get messages that looked like this:

Unable to generate a temporary class (result=1).
error CS2001: Source file 'C:\WINDOWS\TEMP\pmgl4mnt.0.cs' could not be found
error CS2008: No inputs specified

When I grant access to the proper user, everything works great.

Is it possible to configure MEF to use a different directory?

Thanks,
Todd