When I said "original" I meant my original boxed Gold Edition install with SP1, SP2, and Acceleration so I'm OK there.But since you say 'original FSX on XP': note that AiCarriers requires at least FSX-SP2.
Rob

Today I'm moving AICarriers.NET from Program Files to by itself on my C:\ drive and we'll see if I can get it working from there.
I may also try your arrangement of dual installation with both Java and NET versions.
After all the troubleshooting, moving folders, and uninstall/reinstall of Java and Microsoft.NET 4, it turned out that my Avast Free antivirus program was blocking AICarriers.NET from connecting to FSX manually or at start-up via the exe.xml file. That has never happened before. I uninstalled Avast and went back to AVG and now AICarriers is working as it should. My only problem now is I accidentally deleted my good aicarriers.cfg file when I first encountered the problem last week but it's just a housekeeping task to rebuild it. Many thanks to Frank, Cees, Rob, and Seahawk72s for your assistance and suggestions. 
