Yesterday Firefox was updated to version 11. I was hoping that this new version would actually take care of its absolutely crappy behaviour on my Mac Book pro but guess what …. it doesn't. I installed it last night, had Firefox open with 2 tabs (yes, there was 2 small flash-banners on those but nothing fancy) and then went to sleep letting the computer go to sleep.
Today I woke up, closed the lid and went to work. As I opened up the lid and checked Firefox I realized it was very sluggish. Guess what? It now had consumed almost 2 GB of RAM + was running my CPU at 99%. Maybe it is the Flash-plugin that is buggy and has memory leaks but I've had similar experience also with pages without Flash so I think it is Firefox still leaking memory.