I am able to make calls to regular telephones with no problem. However, I can only make one such call at a time. If I try to make another call after the first one completes, I get a "Call Failed" message. To correct this problem, I have to completely shut Skype down (not just log off) and restart it by clicking the Skype icon in my taskbar and selecting "Close" from the menu. Once I restart Skype, I can make one more call.
I am using Skype Version 1.2.0.18_API on KUbuntu Linux version 2.6.12-9-386 with a Cable Modem and Linksys router.
Can anyone please offer any suggestions as to what might be the cause of this problem?
Found the answer, it is in this topic:
http://forum.skype.com/viewtopic.php?t=32290