Skype, which is owned by Microsoft Corp., said in a statement Monday that only a "small number of users" are affected. It called the bug a "rare occurrence" but did not go into details about what caused it or exactly how many people were affected.
Skype says it will send out a software update that fixes the problem in the next few days. It plans to notify users once the update is available.
The bug was first described in Skype's online support forums and reported in various technology blogs. Skype says it occurs when a user's Skype program crashes during an instant message session. In some cases, this can lead to the last IM that person sent being sent to a different contact after they restart the program.