Shoutbox

I have done some searching, and I can't find the option in the settings panel, but when someone sends a group IM instead of making all the members in a slide bar like the 7.x version and leaving the window the size I have it, it makes my window really tall to fit in all the members.

Highly annoying, is there something I am missing in the settings or a way to stop this from happening? 

Thanks!