Playing Caverns of the Troglodytes (first map with the 3 trogs) and one of my chars got killed by Predictable Stab. Game froze during the card animation and the browser had to be closed since trying to resign the battle did nothing. Not sure if this is the same issue as the other person showing the Predictable Stab card staying attached during the battle but for me anyway it completely locked up. Only other thing that stood out as possibilities is that I had 2 Superstitious trait cards waiting to be activated but it had never gotten to my turn. No idea if that had anything to do with the problem.
It may, in fact, be the fault of Superstitious. We've seen issues with trigger-on-death qualities: http://www.cardhunter.com/forum/threads/game-freeze.1058/
Only weird thing is that neither Superstitious had actually been applied to my characters yet as I hadn't had my turn. They were just in my hand.
Ah ha! For that, I get to link you THIS thread: http://www.cardhunter.com/forum/threads/festering-guts-persists-beyond-duration.1016/ Traits currently trigger from hand. As you can see in that thread, Jon has stated they should not do so, and they intend to rectify the problem.
That definitely could be the issue but it froze before I got any notification that Superstitious activated. Could also be affected by that fact that 2 of my characters actually had Superstitious in their hands that hadn't been played yet. So either it had something to do with the Predictable Stab card animation getting stuck like others have noted, Superstitious playing from my hand even though it had not yet been activated on my character, or possibly from the fact that I had 2 Superstitious cards in the hands of 2 different characters that hadn't been activated yet. Damned Trogs! Damn them all!
Check out that top link again: none of the people reporting "trigger-on-death" crashes had actually seen the card trigger. We've all been guessing, based on context, that the game is getting stuck right before the death-trigger stage. We could be WRONG . . . especially if Blue Manchu has updated the code by now.
I think superstitious crashes the game if you have it in hand when someone dies. I'm going to look into this now.