Yes, I'm running the Nimitz, plus several other FSX ships, and using them successfully with aicarriers.
In your FSX/scenery/world/scenery folder, is there a file called trafficCarriers.bgl?
And have you tried moving the AICarriers folder into the main FSX folder?
Not sure why that would make a difference, but that's where mine currently is.
If you try that, don't forget to change the path in your EXE.xml file.
Aside from those two things, I don't see what would be different, other than that I don't have any other entries in my exe.xml like you do.