An Update on the problem.
For the past three days, I have shut the car off with the climate control operating in the "auto" mode and upon restart [either after work or the next morning] the system has reactivated in the same mode it was shut down in. Now, I'm scared to shut the thing off, so, I'm forever fiddling with the temp controls!!
If anyone can shed any light, I would appreciate it. I have searched the archives for my car model and "climate control" but have come up empty. If this has been discussed and someone could point me to the appropriate archive, please do!