chat/trade tab bigger than browser window

I'm playing on Firefox and I also have a external monitor connected to my notebook. This changes the resolution of my screen to 1024 x 768. When I try to enlarge the chat/trade tab (pull it up or down). Sometimes the tab runs completely out of my browser screen - I cant reach the top panel and I cant make the tab smaller.

It would be great if you could look into this problem (You may have something wrong with the scroll bar, cause it doesnt stay on my mouse when pulling on this resolution). On other resolutions its working fine.

did you try full screen (F11)?
if not relogging is the afstest way to fix