We need a bit more information to help you out.
1) Have you made any changes lately to your AHP setup, any X10 modules, or have you gotten *ANY* new electronic devices recently?
2) When you look in the Activity Monitor in AHP, do you see the commands being sent from the CM15A at the correct times?
3) Do you see the RF commands being sent from the remote in the Activity Monitor?
4) Do you have an RR501 or a TM751 (which could be receiving the RF signals and passing them to the power line, independent of the CM15A)?
5) Are your modules "SoftStart"? (when they turn on, do they immediately come on at full brightness, or do they "dim up" to full brightness?
6) If you turn the lights on with the remote, can you turn them OFF individually using AHP?
With these answers, we should be better equipped to help you troubleshoot the problem.