Strange problem with X10 wall switch

I have a decora style wall switch that controls two fluorescent lights. I do not recall the model number but I do remember that I bought it about 11 years ago from Smarthome. I use KR19A remote controller and TM751 transceiver to control the two fixtures of with two 4 foot tubes. This set up has worked flawlessly for over 10 years. But, last week I replaced the fixtures with ordinary ceiling light fixtures. Now, if I put Commercial Electric (from Home Depot) compact fluorescent bulbs in both fixtures, KR19A does not work. If I replace one Commercial Electric bulb with either a Philips CF bulb or an incandescent bulb, KR19A works fine. Wall switch works in all cases. I would like to use CF bulbs but the Philips CF bulb is too big to fit inside the glass globe of the fixture. Is there any explanation for this strange behavior?