Installed the recommend filter (6287) but this did not solve the problem? Any other suggestions???
Just to be clear, you installed the Leviton 6276 in-line between the Insteon/X10 switch and the fluorescent lights? You also wired it with the black leads in the hot path, and both white leads connected to neutral?
That certainly should block noise produced by the fluorescent lights from reaching the Insteon/X10 switch.
Let's back up here. It wasn't stated in your earlier message whether you were using a switch that had a neutral connection. Can we assume the switch in question is designed for fluorescent lights? That means a relay switch with a neutral connection. Most fluorescent lights will not work with dimmer switches.
If you are using the correct type of switch, and the 6287 is correctly installed to block any interference from the fluorescent lights, then the only option left is to increase the signal strength. However, if your other switches work fine, I wonder why the signal strength at this particular switch would be too weak. Could you provide more details?
Jeff