Just to let you know:
When working in the Visual Sourcesafe (vss) program (FB not started), you can right-click on a file and say "Edit". The file wil be hecked out, and FB should open. When I do this with my Fbp5 project file, I get an message [Error executing "c:\program files\..." "D:TheFileName]. Both the program location as the filename are correct. In the message the last quote is missing, maybe that's the problem.
Other applications seem to work ok for this.