Why do I get the error C1033: cannot open program database in VS 2010

To solve this problem, I deleted the pdb file (after I backed it up), then builded it.

I get this error all the time when I am running a project in my dropbox folder. It seems that dropbox is backing up the .pdb file at the time I'm trying to build.

Usually it works after one or two tries.

I unchecked the 'Run this program in compatibility mode for Windows XP (Service Pack 3)' checkbox and it works now. Originally I played with the other options but not this one !