See this link for more ideas: http://forums.asp.net/t/980517.aspx
I got this error. I tried a variety of things. Changing “CodeFile” to “CodeBehind” broke things. Changing Class names didn’t quite work. It would work if I hit debug from VS but publishing failed. Just on a whim I unchecked the box that allowed for precompiled sites to be updated (I don’t need it, some might, but I didn’t) and bam! It works!
Shiny 
