Hi ...
Ok, I just tested it under Safari, FireFox, IE7, IE8 and IE9 on both Microsoft Windows based computers, as well as Apple Mac OSX based computers.
I can't duplicate the problem ...
Both the "Quick Reply" window and and main "Reply" window (under "Go Advanced") appear in their proper postiions.
Try the "Quote" and reply function again and confirm it's still not working properly for you.
Thanks ..
Regards,
Doug