Are you sure that the batteries in your CM15A are good?
If you go into the Hardware Configuration in AHP, does it show a green light next to the battery status?
If the batteries are not good, or for some reason the CM15A isn't running properly on batteries, then unplugging it will clear the memory, and timers won't run.
You should test the CM15A with a "fixed" timer (like the 1:50 PM / 1:52 PM test you did), but DISCONNECTED from the PC.
That might give you some clues to see if it only the dusk/dawn timers that aren't working properly, or all timers.
Also, what is the dusk/dawn resolution set to in AHP? You might try changing it to a higher/lower number of days (at least for testing), and then re-downloading and re-testing.
Check the dusk/dawn times in that list, to make sure they match up with the correct times for your location.
Also, make sure your time zone is correct in Windows. I've seen reports (early on) that having the time zone incorrect, even though the local time is correct, can mess up dawn/dusk timers.