We have had this problem occasionally. Other than some read-only tables, we also had a base class library and a base form class that were set to read only and thus had a problem re-compiling and the project compile would fail with a "Can not update cursor" warning. We had to write a hook into the project to reset the attributes for all files in the project to read-write then after the compile set them back to read-only. The reason the are read-only is we use VSS and they were not checked out by the person making the build. This problem was not consistent so that we could track it but the hook kept us from having to check out everything in the project to make a build and we haven't got the error since.

Informative error isn't it?