Shoutbox

When I send files to my friends, I used to drag the file to my task line.
I pointed on the MSN Messenger, and got all conversations up.
Still holding the mouse button, I then moved to the conversation I wanted, got the one up in front and then dropped the file in the text-field.

Try this with Tabbed Chat, and you'll see the problem.
When I point to a "background"-tab, nothing happens...

Does anyone understand what I am trying to say?