I was playing around with some different revision schemes in the recent past and now PDMWorks won't let me check in one of my drawings.  It says that the revision has already been used...however, that is not the case, in fact while it should be Revision F I bumped it to Rev Z just to see if that would work and got the same error.  Tech support's answer after looking at the issue was simply "You'll probably have to redo the drawing."  Not a very good option, there was a lot of work in this drawing.  Any ideas on what could be causing it or how to fix it?