Like already told, try to make skins for WLM instead of making them for MSN 7.5. It's a lot harder to reproduce a skin with the new WLM resource structure causing a lot of trouble than immediatly starting a skin and getting used to this new way.
Skinning master
theunknown is compiling a modified version of the msgsres.dll will make skinning WLM as easy as MSN skinning was. For the moment, you'll have to use all the tips and tricks posted on the forums to skin Windows Live Messenger...
But, not bad at all, se!
/ 
