Hi Bill,
So at some point in time, not too long ago, you were able to turn all lights ON and OFF from the computer but recently that changed and you can only turn the lights OFF? I would unplug / unscrew anything you added (including CFL lights) since the system started to become unreliable, until you find the culprit... You probably saw my post earlier, I had a similar issue except I couldn't do anything at all anymore.
Something in the house is interefering / stealing the X10 signal and it seems that it may be strong enough for the OFF commands but not enough to execute ON commands. It could be that maybe you started switching to CFL bulbs and in the beginning, when you had 1 or 2 it wasn't a big deal, but the more you added the more you noticed stability issues? Personally I have 2 CFL bulbs in the house (not controlled via X10) and most other bulbs are dimmable LEDs. The only issue I noticed with the LEDs is that they are loud(er) than normal bulbs when on and dimming is different; I had to adjust the dim percentages in my macros to have the same intensity as incandescent bulbs.