Same here. Win2K and random crash within 24h hours with 6.12 and sysreset 2.53. Everything was just fine before that with 6.03.
It MIGHT be the so called new DCC exploit but note that I already tried this summer to upgrade to 6.1 and the SAME thing had happen and pushed me to downgrade back to 6.03. At this time it wasn't a big fuss so I just forgot about it...
Btw, DrWatson traces are useless as ever (just a c0000005 error as usual and a faulty addressing in <nosymbols> around 0x0042bxxx or 0x0042cxxx), but if it can be of some interest for you don't hesitate to ask for...
Now I'm just cornered between a 'dangerous' 6.03 with exploit and a crashing 6.12...
