You are using version from Nokia Store?http://store.ovi.com/content/20924
Symbian specialist until 31/01/2013 with interests in Maemo & MeeGo but an aversion to Windows!
Skype doesn't support Video Calls on Nokia!
For Video Calls, I highly recommend using Fring. Both Video & Audio call quality is really good.
You can download it from Store or www.fring.com/m
Hope this helps.