I had one yesterday as well but luckily it only happened an hour before I woke up so not much time lost there. Last night it happened 10mins after I went to bed so ~8hrs were lost, time to adjust voltages on my OC and see what happens tonight.
Wasn't able to fold for the last 3 days and will probably not be able to fold in the near future, due to my parents forbiding me to have my computer turned on for folding, while I am not using it.
. Will have a word with them, to try to get back for some time at least, but don't really know yet.
Heat is a pain in the ass, I am just playing with my settings now to OC a bit more. I have not got much of a clock atm my i5 750 is only on 3.4 but is already at 67 degrees under stress so I need to tweak my voltages down if poss but up the OC, gives me something to play with on my week off next week (once garage is cleaned out)
SMP is sucking CPU juice but GPU Tracker can't see it, GPU folding is a non-starter.
EDIT: Reinstalled GPU Tracker, everything functioning again; bye-bye 5% on a >900 point SMP WU, and I still have never seen the PPD on my CPU.
EDIT 2: It freaked out with the same/similar problem, second reinstall in the past day. Also fizzed out at 5% ~450 point SMP WU. Not going to touch the power saving options and just leave it in always on to see whether it was me, also downclock the GPU to 959MHz.