Hi CodeQuest,
When you rename an item the .aspx and .vb or .cs code-behind files are renamed, but the class names contained within them aren't. The reason for this is because you might have code in the project that assumes that those files have the same name -- in which case automatically renaming them could break things.
There is refactoring support in VS 2005 that you can use to automatically go through the project and fix up all references for you. This is one feature to consider using if you want make a change throughout your project and its dependencies.
Hope this helps,
Scott