Shoutbox

http://www.msgplus.net/scripts/view/157-Enhancer/

I use tabbed chats, and when I use it, it absolutely won't allow me to close a chat window.

if you checked the thread or the last updated, it was last modified in 2008... therefore it was made for WLM8.5... what it does is normally very version specific and to make it work would probably require a full rewrite

edit: apparently it was 2009 for the script db but i doubt it was changed to WLM 2009

Are you sure Enhancer is causing this? Did you try the same thing with the Enhancer script disabled?

I just downloaded it and it seems to work fine in combination with tabbed chats for me. Although it may be a specific setting within Enhancher, I just tried it wit its default settings.

Windows 7 Home Premium x64 (6.1.7600)
Windows Live Messenger 14.0.0416
Messenger Plus! Live 4.84.0.382
Skin: fuse 1.0.3

Of course I'm sure...

Disable the blinking windows while you have some tabbed chats open, then try to close the tabbed chats.