Before trying to isolate an issue, it's always best that one is running the latest Skype release. Which may in itself resolve the issue.
A new version has just been released September 1, 2011:
Please download/install this version from here, when prompted click the open or run button: http://download.skype.com/SkypeSetup.exe
This new version is 220.127.116.11 to check what version you have, using the main Skype client window please do:
Help -> About Skype