I have a 2002 Camaro Z28 with a 6-speed manual tranny. It's now allowing me to put it into reverse while I'm trying to get it into 5th gear. It doesn't do this all of the time though. It actually doesn't GO into reverse... it just grinds. It never used to allow me to even go over that far while trying to shift unless I was already stopped. Does anyone know why it's doing this?... and what I need to do to fix it?

Thank you very much!
John