My 895 does that too, but fiddling with the button unsticks it. I could fix it but I hardly touch the radio - it sits on one channel all day long. Poor unloved old 895...
You might have to disassemble the radio to fix this. Just be careful and keep track of what screws go where. With a bit of luck and a steady hand, you should be able to unstick that key within a matter of minutes - the radio is big and easy to work with, and you can add a discriminator tap in there too while you're at it if you're feeling froggy - do a google search for destructions on that.
Bright side is at least there's no warranty to worry about voiding on that bad boy - it's WAY too old...
EDIT: Bah, I didn't type fast enough. Anyway glad to hear you got it working.
-AZ