Via a Skype Public Chat on Skype 3.x, we have just received the following statement re the problems that occurred on Sunday and were reported on Monday:

Skype’s engineering team has concluded their investigation into the outage that Tom Keating alerted you to yesterday and I wanted to share their findings with you:

Users of some Skype Certified devices experienced login problems on Sunday when a server-hosting location experienced network connection difficulties. As a result, some services became temporarily unavailable. This has since been rectified. The scale of the problem was minor and we've taken appropriate precautions to avoid it happening again.

Seems like it was not only a Skype server-hosting location that had "network connection" difficulties on Sunday; appears that a truck crashing a power transformer brought down GigaOm's hosting service provider on Sunday also. Signs of these trying times of getting the Internet to be a five nines reliable network.