hey aeyoun, thanks for replying.

I notice this also with Opera Stable:

Version: 24.0.1558.53 - Opera is up to date
Update stream: Stable
System: Mac OS X 10.9.4 64-bit

The odd thing is I actually don't get any crash report or notification. It simply reboots the app, which is why it's a little perplexing.

Ah, the Mac subforums seems to have this issue logged already. Will continue there. Cheers!