Running the dedicated 20amp service is what did it! I have had homes that gave me fits and once we ran a dedicated line for the A/V system, the X-10 has worked perfectly. If you do start to encounter problems again, you may want to look into an amplified coupler if you don't have one.
On a side note, Panamax is the best surge protector but is the worst for X-10 noise problems. If you start to see problems again, try unplugging the Panamax and see how it works. You may look into filters if this happens.
Chris Couture