I've been changing out bulbs and going to the LED lights. I really like them and have swapped out 9 of them so far.
Yesterday though, I ran into a different situation. The outdoor light over my family room sliding door is controlled by and X-10 switch. I've done that for years and it is very handy as this is the most used door in the house.
The light was "off" and I screwed the bulb in, and it lit partially. Not full brightness, but just dull. When the timer came on, it went to full brightness. Having it half on 24 hours takes away some of the savings, but I guess it is still minimal security at night after the normal off time. I also know not to replace the other X10 lights with LED. They work fine with CFL.