It seems that client freezes and crashes because of the chat. I almost always sit in the chat I get these freezes constantly, today I changed settings of the chat rooms to autojoin and client started to freeze when I log in. Sometimes it takes from 5 seconds to 3 minutes for that but usually it's instant.
Now my client runs perfectly fine without being in any of the chat rooms. If I join one of them, my client goes \*boom* after a few seconds.
Freezing and crashing started with 06/01 update (start of the 6.12 cycle).