asp.net version

I am running into a parser error:
Parser Error Message: Could not load the assembly 'App_Web_isudumlt'. Make sure that it is compiled before accessing the page.

I have searched the forums and everything states I am trying to run asp.net 2.0 programs on a server that has asp.net 1.1 on it (or just the opposite).
I checked the server and the default web site is configured for asp.net 2.0. I am using VS2005 for development and I have asp.net 2.0 installed. So why do I keep coming up with these parsing errors? Is there something in my web.config file that stipulates the asp.net version?
What am I missing?
Thanks,
Mark
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