No Reverse!

[Dan DiBiase]

So my car won't go into reverse. When I try and shift into it, it feels like something is 'blocking' it. I tried to let the
clutch out a little and see if it would go into reverse, but nothing except a little grinding. I drove the car to do some 
errands and even after fully warmed up, no go. All forward gears work fine. Any ideas on what the problem might 
be? Oh, this is a manual 6-speed. I'm bringing it to the shop tomorrow but figured I would ask for potential issues.

 Dan D
'04 A4 1.8Tq MT-6
Central NJ USA