I killed my Firefox as it was behaving a bit slow and I thought I will replace it with Opera as my third browser, behind my trusty Chrome and Safari. Hence I downloaded Opera 12 to give it a try.
Bad move! Punishment for not reading this before I went ahead. Opera 12 evidently doesn't like Flash and will freeze cold when it encounters one; not reacting to anything. I had to force quit whenever this happened.
Hope an update to solve this problem comes soon. Or else I will remove it and stay away from it for some time. It is actually a pity as I kinda like the UI and ease of configuring the various settings...