If your tab blinking for no reason drives you crazy, there is something you can do about it. Click on whisper and type: "/w yourname" without quotations and press Space. This will open a whisper box to yourself. Now type something to yourself, wait for it to get back to you and then x out of the whisper box. Voila. No more blinking.
"/w yourname" command is also useful when you want to test filters in chat.
Good luck