I would like to reiterate what Mike said about the junk in old links,
Having gone through the same process of saving old HL created links and then piece-by-piece cleaning out devices, I finally had to follow the original advice of all the veterans here. I was tired of the false signals etc. In other words, I started from scratch with a complete clean ISY and did a complete clean of all devices and setup new links.
Since I was feeling more comfortable with the ISY and with how I wanted to lay out my scenes and programs I found it went very easily. One valuable tool I used from my first ISY install was the Topology. It provided me a checklist of devices and locations so that I could just sit at my console and get it done!
The end result is a much cleaner setup and operation, you can forget spurious X-10 signals or other conflicts.
JIM