Skype, Microsoft Corp's online telephone and video service, said on Monday that some users are unable to make calls because their settings show that they and their contacts are off line, even when they are logged in.

Affected users are unable to change their status, but they can use instant messaging and Skype for Web services, Skype said.

"We're working on a fix for this issue and hope to have an update for you soon," Skype said in a blog post. – Reuters