Check the SkinTrace file if messenger refuses to open (that's assuming you've set <TraceFile>True</TraceFile> in your SkinInfo.xml) and it'll tell you what line of code is causing the problem, and which definition and style sheets were last loaded (it'll be in one of those).
Sometimes elements cannot be moved outside of other container elements and this may cause problems.
Skinning takes a LOT of trial and error. It took me 2 days of trial and error to just reposition a picture to be aligned with the display pictures in the conversation window.
We can give you advice and help and stuff, but we're not gonna make you skin for you