I don't remember anymore - running 11.0a now. I'm using nightly builds since ~2009 and haven't experienced any issues so far (really - not even a random crash). The difference is so huge in overall performance, I don't want to go to the "stable" release anymore.

The only problem are some less common plugins, but adblock and firebug get updated within days... and I just switch to the latest official release for quake live.

"I don't remember anymore - running 11.0a now. I'm using nightly builds since ~2009"

Likewise. I also have several extensions enabled and generally have 30+ tabs open all the time, sometimes many times that. I have had an odd crash but very rarely.