Reports that users are accidentally getting logged in as different users?
Using Jamroom
We had one other site report this to us a bit back - I believe the problem lies in the "session sync" function in the User module, but we've never been able to actually replicate here. However, Users 2.2.0b2 has all new session sync functions, so updating to Jamroom Core 6.1.0b2 and the latest beta modules can hopefully help this.
I know it's a beta release, so if you'd like to do that let me know your site login in a ticket and I can make sure you get updated correctly.
Hope this helps!