Microsoft said on Thursday it was deploying a solution to the problem, according to a on Skype's Heartbeat blog, which is devoted to bugs and system problems affecting the service.

"Over the past 24 hours, we have started deploying a fix on our end that resolves the log-in issues. We apologize for the inconvenience," Skype official Jennifer Caukin wrote in the post.

A Skype spokeswoman confirmed via email Friday afternoon that the issue is fully resolved, but declined to comment on what caused the problem and how many users were affected.

The problem apparently started last weekend, according to multiple discussion threads posted in the of the Skype support forum, where affected users flocked to complain about the problem, including some who use Skype for work.

The problem affected Skype-certified phones from vendors including Panasonic, Linksys, GE and Netgear.