12/9/2008 Patch -- Broken Buttons -- Solution
 

Any problems with the Raid, Group and potion windows not working is caused by <labels> in the windows.

They need to have the following tag added to them:

<Style_Tooltip>false</Style_Tooltip>

Apparently, without this tag, Labels now overlay buttons and such and prevent the function of the buttons.

I fixed this in the UI that I use for myself by doing that until the author has a chance to officially patch it.

I've seen several people in game having these problems since the patch with custom UI's and since I figured out how to fix it for myself, I figured I share the info so others can benefit.

Hope that helps.