OK, I had the exact same problem of the Activehome Pro losing 1 hour. The upgrade to version 3.203 earlier this year seemed to solve that. For the last 3 months there has been absolutely no problems -- I didn't have to touch the CM15A unit at all.
On Sunday night that changed -- the timer lost 1 hour and turned everything off early. So I took it to my computer and plugged it in only to get the old message that this USB device was not recognized. Exactly the same thing that had been happening before. So, I unplugged the batteries and disconnected the unit from the power. This reset the unit and it was recognized by the PC.
I reset all of the hardware configuration, battery life, and downloaded all of the timers.
The following morning the lights turned on correctly but, that night everything turned off one hour early again.
I repeated this procedure again. Same problem every night since then.
Nothing has changed in the house electrical setup. Nothing has been added or removed. Same light modules same controller same locations. And, given that this had finally begun to work correctly (after close to two years of trying to get a resolution) I was satisfied. I've been using X10 home controllers for over 20 years and this is the first unit that I've had from them that not only doesn't work well but also which they don't seem to be interesed in fixing.
I suspect that this current issue is a software bug and might be related to the time/date in the unit (the year 2000 problem in 2006?). I also tried changing the dawn/dusk settings since that had helped before. Didn't do anything useful this time.
So, I've just reset the unit one last time and if this fails I'll go back to the CM11A Active Home unit. That never failed and I've had that for years -- it just didn't have the capability to set more than one unit for dawn/dusk timings.
Ah well. Chapter 7 seems more reasonable than Chapter 11 at this point.
Bill t.