Sorry about the confusion...after reading it i see i wasnt very clear. Ill start from the beginning. I have replaced the original switches back in the boxes. I have a regular dimmer and then a simple on/off switch (original switches, not X10). These two switches control my living room ceiling lights. I want to install my X10 three way switches that i picked up yesterday. Out of the boxes, attached to the original switches are a black, white, and red wire. The black wire is connected to the "common" screw. I tried to switch the original switches with X10's, and used the black wire as the common wire. Once connected though, i could only turn on the lights with the dimmer X10 (master) swith, but not the slave switch. I can turn the lights out with either one. Is this a little clearer? i know i tend to babble sometimes...thanks for your help!