I think to recall a conversation with freemangordon about skype video calls.
Different versions (and OS) could use different video codecs.

If you are using 720p gst libs from here:
http://talk.maemo.org/showthread.php?t=77695
Take care that last version is different from the previous one also for the codecs used in skype video calls.

I posted the "works for me" previous version here:
http://talk.maemo.org/showpost.php?p...postcount=1350

If you are not using 720p libs, sincerely i have really no idea of what is supposes to work and what not.