Meh, standards aren't that bad to fix, especially reverse. It's right there on the end, and requires minimal disassembly. A trans. shop will be able to take care of that, no sweat. You could need a new gear, as they don't have a synchro on reverse, iirc. Could be the shift fork is out of alignment, but I think you'd have problems with 5th to, if that were the case.