One good troubleshooting tool is to set an ON ERROR in the command window before compiling. I just call a messagebox() do display the error info. Of course, it may not be an error... In any case, if the messagebox fires, you can see the currently processing file on the status bar. If you don't do this, the status bar message is removed and you can't tell which file causes the problem.

As far as read-only files go, you can try checking out all files in VSS and building. I've found that changes in our setup have allowed checked out files to show up as checked in trough project manager and vice-versa (mostly due to switching between VSS and Source Off Site).