Since upgrading to v1.61 I've been getting a lot of the following:

It always corrects itself if I rebuild the solution, but if I leave a form and come back to it later it frequently re-appears.

-Larry

Thanks for the suggestion. I've tried that route but I'm still getting designer errors. I'ts only happending on two forms but so far I haven't been able to figure out what is unique about them. I did have an issue on one where I had dropped a tab control. When I later deleted it the tab definitions were left in the deisgner file which I manually cleaned up. When I get some time I'll try recreating the form and see if the issue persists.

-Larry

That error shows up all over tons of forums throughout the Internet.  I found this KB article from Microsoft that says that there is a hotfix... I think it might be included in SP1 of VS, because I have a System.Design.dll with a newer version than this one.

http://support.microsoft.com/kb/921019

The article says System.Design.dll v2.0.50727.193 should fix the problem, and the one I attached is the v2.0.50727.312 from my computer... I have VS2005 SP1 and VS2005 SP1 Vista Update installed.