Pete,
I had ALL sorts of noise generators when I jumped on X10 (a couple of months ago, and it seems like forever now). I ended up getting a bunch of noise filters (4-15amp & 15-5amp). I've used all of them in the process of addressing my issues. I recommend you go on eBay and buy a bunch of the 5amp filters and use one for each power strip to make sure the strips or whatever ends up plugged in doesn't cause noise. Of course, this exercise may help you determine what you REALLY need plugged in. Sometimes, for convenience, we left stuff plugged in (phone chargers, laptop chargers, etc.), but now, everyone at home is "trained" to only use the power strips that are plugged into a noise filter.
BTW, the biggest noise generators for me were my sound system (component rack), my washing machine, my wine fridge, and my high-end UPS system. They overpowered most of the smaller filters in other parts of the house until I put 15amp filters on each of them.