We have seen the same issue. Are you source controling your project files? If so, make sure you are not putting the user specific files into source control. Also, make sure none of your soulution/project files are read only for any reason.
You may also want to drop the Crytstal Report references and readd them.
I don't remember which of the above eventually solved this problem, but it was annoying.
Then, finally, do what we plan to do... Drop Crystal Reports, run away as FAST as you can and don't look back.
Bob - thanks, I'll give it a try.
(though sadly, not that last part... )
Seems that it has to do with upgrading Crystal Reports. This happened when upgrading to XI. The problem is that while you can have both 9 and XI installed at the same time, Visual Studio always want you to use the latest, even though you have bound to a specific version. If you answer No to the upgrade question, Visual Studio 2003 *removes* the Crystal 9 references!