I know the bug tracker is the place to report bugs, but thought it might be nice to have a thread with workarounds instead of having to dig around in there for the problem you're having.
Some of the ones I've noticed and found ways around in 0.31.12:
Dwarf Cancels Clean Self: Area Inaccessible
This consistently happens to me whenever I make soap. It seems that the dwarves will go to the soap stockpile, grab a bar and then for some reason can't find their way to water. The only workaround I've found is to not make soap, and forbid any that might turn up; then they have no problem going to water and washing themselves.
This can be really frustrating as it's a task you can't disable in any way - if they need surgery they'll continually run off to clean themselves and fail, which brings us to...
Dwarf Cancels Surgery: Patient Not Resting
Dwarves really don't like surgery in this version; they'll come up with any excuse to get out of it ("Sorry Doctor, I need to go and Clean Self!"). I've found that surgery will work, however, if you disable all of the patient's labours and remove him from the military.
Make Cast lasts forever
If you have gypsum plaster, your doctors will sometimes decide to make a cast for a broken limb instead of using a splint. However, when they do this they'll go to water with a bucket and then get stuck until an urgent need pulls them away. It seems like making casts is actually impossible at present, the only workaround is similar to the one for soap: don't acquire any gypsum plaster, and if you do, forbid it.
Can't cut clear glass
Okay, so I'm not sure if this is down to me not understanding the interface of the jeweler's workshop - if so, my apologies. It seems, though, that the option to cut clear glass into gems has disappeared from the jeweler's. The only way I was able to get them to cut the clear glass was by assigning a manager and using a production order.