I believe I read somewhere in the latest release notes that the bug was fixed that caused "Sessions" to be combined.
I just ran two Sessions close to each other that were combined, restarting HE Manager in between the sessions.
The old HHs were still in the HH folder, which may be the cause.
(The latter is a different issue I am having...the HHs are not being moved. I have it configured correctly and have reconfigured the "move" operations a couple of times. But I'll post on that in a separate thread when I have time...)
Thanks for the great product!