Skype's Support Network has been reporting how Skype text messages have gone to another contact.

One user said the problem happened after the June 2012 upgrade. Sometimes when she opened chat window with some contact, It lists all latest messages from that person although I have already read them.

Few days ago one friend from her contact list has received few messages she had already received before from another skype contact. The messages appeared to have been sent by her. Skype investigated and found that there was a bug in its software and has promised a fix in the next few days. Older versions of Skype do not appear to be affected. 

Skype said that the problem occurs only when a user's Skype client crashes during a Skype IM session, which may in some cases result in the last IM entered or sent prior to the crash being delivered to a different IM contact after the Skype client is rebooted or logged in as a new user.

Although Skype can't work out how many users may have been affected by this error, we believe the number is small given the specific circumstances under which the error occurs.