Rasnell,
I apologize for the long delay in responding to this thread, and I'm sorry to hear about your frustration.
I have logged this as TT #2027, and hopefully we can get this changed. Meanwhile, I realize this doesn't help, but a few suggestions if you're still interested in playing:
1. Always back up your games, preferably between each sim if that's not too cumbersome.
2. In a case like yours, as a temporary measure, you could try password-protecting the manager identities. That will require an extra step of you, but it will prevent you from simming without realizing who is logged in.
Like I said, these are workarounds and preventative measures, not a true fix, but I have requested that Markus look at this.
Thanks very much,
Steve