That is a problem with the Flash plugin. You can check for problems caused by recent Flash updates and try these: *disable a possible RealPlayer Browser Record Plugin extension for Firefox and update the RealPlayer *disable protected mode in Flash 11.3 and later *disable hardware acceleration in the Flash plugin *downgrade to Flash 11.2 or 10.3 *http://kb.mozillazine.org/Flash#Flash_Player_11.3_Protected_Mode_-_Windows *https://support.mozilla.org/kb/flash-113-doesnt-load-video-firefox *https://support.mozilla.org/kb/flash-113-crashes

I am sorry for the late answering. Thanks for helping me, cor-el. I have downgraded Flash and it seems everything is ok now. : ))