Possible bug.
I noticed that when I shoot in P mode using exposure bracketing with one full step spacing, that my camera sometimes crashes on recording the second raw frame. At which point I have to take the batteries out of the camera and restart it to make my camera function again. the same bug also occurred on my friend's SX10-IS when using the same settings I did.
Update, doing a little more research here, and it appears that .DNG format is what's causing the problem. When I use exposure bracketing with .DNG turned on, it locks up on both our cameras here, but when we turn it off, it works just fine.