Even with disabled 'private message notification' in Xchat-Trayit keeps blinking when recieving private messages - i had it enabled during startup of xchat.
Logged In: YES
I can't reproduce that. Are you sure it's not a highlighted message, or soemthing else causing the flash?
I just don't see any problem here.
Stated WFM, 3.5 year old anonymous bug, close it!