I wanted the goblin's clothes to look scrappy and homemade, so I added a load of overlapping patches.
I was half way through the stitches on the patches when I changed my mind about how to do them, so I had to go back and erase the old ones and redraw them. Lucky I was using layers for them and the patches so that wasn't a big deal.
Mudbox seems to have been behaving OK on the laptop, which is good. No idea what I did to change that. Might have been a defrag or cleaning up some space on the C drive, or moving the data off the swap drive.