Sometimes, when you login to Skype (usually after new release or problem with servers) , you don’t see your contacts or you see few of them but not all of them.
In any problem regarding contacts, you should do the follow:
1. Logoff Skype.
2. Open "my computer" and browse to the following directory:
C:\Documents and Settings\YourUserName\Application Data\Skype
3. Delete the file called: "shared.XML" or "shares.XML" (depend on version).
4. Login to Skype