Skype identified the issue with the strange messages (IM !)
One of the World's most popular online video chat company Skype had identified the issue and working on the fix that's real tough. Skype expressed apology to all the users and said that they had identified the vulnerability in the system that was causing private instant messages with one contact to be sent to another without permission or warning.
The defect was: In some typical crash scenarios the last IM entered or sent prior to the crash being was delivered to a different IM contact and that was happening after the Skype client is rebooted or logged in as a new user.
Per Skype its yet to be determined that how many users have been affected by this, but also think at the same time that number would not be huge as this seems to be isolated scenario. They said that Skype 5.9 and 5.10 clients on window had the worst impact out of the other rolled out Skype version on different platform.
-CB