If it was working and now it isn't, then there must be a change somewhere.
If it works when close coupled in the same outlet on the same circuit, then most likely it's a noise issue (especially if it was working before).
If software was working and now crashes then there is a change or a corruption.
Following the OP's theory, if a Windows computer suddenly crashes (for no apparent reason) it should be tossed out and replaced with a Mac or a Linus based system.
It looks very much like a software corruption to me. The AHP software does not uninstall cleanly and easily, but a thorough removal and reinstallation of AHP would possibly solve the software crashing issue.
Each and every X10 set-up will be as individual as the user. There are many issues that can affect an X10 system and without a thorough inspection I don't think anyone here can say "yes, it's definitely THAT" - A suggestion of "it could be THIS, THAT or THE OTHER" is the best you're going to get.
Diagnostic tools are available that will assist in tracking down X10 issues - a simple search will reveal them. Add the word VOLP into your search and you'll hit the best of them immediately.
Diagnostic tools for computers are also available and I would think that someone who develops computer applications (and has been in information technology) would have a better grasp than many other here on how to diagnose computer crashing issues.
My car has an engine fault light on the dashboard - should I trade it and get a new one?
However, if simple timers are all you need then it's probably not worth the effort of trying to obtain a working and reliable X10 system.
Please let us know when you have your modules on Ebay so that we can all fight over them