I took the picture last summer at an open-air museum just west of Minsk. Everything else there was nicely restored, but this tank was off to the side with some other damaged pieces.
I have no idea what this is, it doesn't match any of the AFVs I know.
I took Antoni's advice and posted all the photos I took at that museum on photobucket, including the mystery AFV, of course. Now I'm trying to figure out the whole "photobucket" system, what my URL is and how to attach it to a message here.