I've had some bad nights, but no cursed characters. I *have* noticed that rolling hot seems to go with game mastering, in my group, though.
The worst case of it I can remember happened when afriend and I were co-GMing Sorcerer (which involves tons of 10 sided dice). The players got into an introductory fight that they should've won: 1 bad guy of PC level against 3 fully prepared PCs. No surprises, no tricks.
The monster critted the first two guys in about nothing flat, and the third player *barely* took it out before also needing serious medical help. After the fight, my friend and I just started rolling hits, to see how long the streak would last. The players watched us taking turns rolling the dice. We got twenty or thirty hits in a row - not a single miss, and most of them were also criticals.
We never played another session of Sorcerer.
(I've also had some characters that always rolled hot, but nothing like that.)