Shoutbox

I'm having a problem applying skins to my Messenger Plus. When I download the skin and try to open the file, I get the error message "The file you tried to load does not appear to be a valid Messenger Plus! skin pack".
I've tried multiple times with several different skins and get the same error each time.
Has anybody else had this problem, and if so, how can I fix it?

Related information: I installed Windows 7 last night and have since downloaded version 14.0 of Windows Live Messenger (the version before the current version) and the most recent version of Messenger Plus!.

If anybody could help me with this, it would be greatly appreciated. I'm fairly sensitive to cosmetic changes made to my system, and I miss my old MSN look.