flash causes system freeze (any browser)

I have this problem already couple of months, tried to uninstall/reinstall flash and browsers couple of times with no luck.

The problem is simple, when I try to load a page with embedded videos on it (even if I don't hit the play button), the whole system freezes. In chrome a window pops up saying flash pluggin stopped responding, in opera nothing shows up it just freezes. All you can do is to open task manager, you may as well possibly task to other open programs but it takes lot time to respond and they get frozen then anyway. Until now it always used to unfreez after 2-3 min, asking me whether I want to stop the plugin or not. But now, it freezes and I cant do anything at all, when I press end task in task manager, it does nothing, when I press end process, the whole PC freezes and I have to reboot it. When I disable flash plugin in browsers, all pages load just fine but then I cant load any videos at all.

Sometimes it doesnt happen and I cant even tell on which sites the problem occurs, on which not... usualy it freeze with youtube videos, but sometimes it doesnt. Mostly sites with embedded sport highlights work OK, but its not a rule either.

WinXP, SP3, 32bit. Chrome/Opera/FF