Since this ROM has an optimized build.prop, and since changing yours back to stock seems to have fixed your aria, I'd recommend going back to the stock build.prop as shipped by HTC and/or the one sent with the OTA update for the stock ROM.
How comfortable are you at adb push/pull commands? That would be the easiest way to do it.
Well the thing is stock Aria rom didn't support GSM Only, that is the weird thing. (Same with the Inspire stock rom) But I see where you are going! That is one of the few things I hadn't tried, mainly because of what I said just there: Stock rom doesn't support GSM Only so assumption was that the stock build.prop wouldn't help me.
adb push/pull is how I was testing other build.prop's that i had made changes to. The part I wasn't sure about was if the changed/replaced build.prop would take effect right away, reboot was required and/or if a full reset was required. (For some reason I thought I tried replacing the build.prop on your rom with adp push and it didn't work and that I had to use update zip & also factory reset but I've tried so many things now hard to keep em all straight! lol)
Anyhow suppose I should try the stock build.prop & see but honestly I have very low hopes as I said above.