It is highly unlikely to be the fault of your Tissue-Tek :) I cut the same
tissue with it.
Rolling is a different affair. Here are some parameters you should play with
before giving up and cussing:
a) as mentioned, temperature in the cryostat, and humidity (the room, too)
b) the position of the anti-roll plate (should just overlap the edge of
the knife)
c) the *condition* of the anti-roll plate - if it is all scratched up, you
may want to get a new one. It doesn't take much to chew up the plastic, and
it can be the last resort which solves all your problems.
I find that I cut best at 10-15 microns, -22 chamber and -20 for the block.
Good luck and don't give up!
Heather