I have posted this recent problem in the old N900 thread with similar issues:
http://talk.maemo.org/showthread.php?t=85606
and also at
http://community.skype.com/t5/Other-...ts/m-p/1001536
and at
http://discussions.nokia.com/t5/Maem...1536358#M35460

I have tried all flavours of "clear device"/"restore settings"/reflash/manual rm... and nothing helps. I deduce, that the fault is at the side of skype central servers or some kind of protocol change/incompatibility.

Paul