Skype spokesman Villu Arak says that last week's massive outage was
caused by a restart of our user’s computers across the globe.
He said that as all the customers rebooted after receiving a routine software update Skype’s network resources were stressed.
"This caused a flood of log-in requests, which, combined with the lack of peer-to-peer network resources, prompted a chain reaction that had a critical impact," he said.
Normally Skype’s peer-to-peer network would heal itself but this time a previously unseen software bug within the network resource allocation algorithm which prevented the self-healing function from working quickly.