Noisy rear diff.....

[Fin]

I've noticed for awhile now that I have a noise coming from the rear of the car that hasn't always been there (I had a Zexel-Torsen posi bought from SLP installed by the dealer last spring). Anytime the car is moving, it sounds almost like marbles rolling around. It's gotten pretty annoying lately, and the last time the car was in the shop, I had them check the fluid level (which they said was fine). Also, alot of time as I start from a stop, or shift through the first couple of gears, I get a 'clunk' that seems to come from the rear (happens when I give the car gas after going into the next gear). Also, it seems that sometimes if I downshift while sitting still I get a slight noise from the rear, similar to the first noise I described, only heard as I go from one gear to another. Drivetrain-wise, all I have is the Torsen LSD & a B&M Ripper. Any thoughts?