We recently ran into a problem in which when we updated a user's photo in mysite, it automatically updated another user's profile with the same photo. On further researching, we found that both users having the same username but they are in different domains. for eg: domain1\user1 and domain2\user1.We have a connection to AD for both domain1 and domain2 and a trust established between the 2 domains.Any fixes for this issue other than changing the username of any of the user?
One thing you can do is to set the profile picture user property direction to Import instead of Export, assuming user1 uploads the picture in SharePoint. On Export, the picture overwrites the AD profile picture. In order to change the profile picture (on Import) you have to change the profile picture in your AD (domain1 and domain2).