Stop suggesting this as a cure for every problem anyone has on any ROM.
Your advice is going to screw someone up badly.
You are suggesting he changes half his firmware, a technique only proven not to screw up OrDroid ROM and well proven to screw up pretty much every other ROM, but you've ignored that he is using Android Revolution HD.
Your firmware swap has been specifically proven to louse up ARHD. So don't suggest people try it!
Plus, he's not having any of the issues that swapping HBoot versions will supposedly cure. You've done testing on how HBoot versions affect battery temp only. You can't suggest that people try it to fix battery calibration and reboot issues. There has been no testing on that. And trying a firmware hack to fix things it's been untested on is really risky.
DjLukeW, the first thing to try is a full battery calibration to see if that helps with the screwy battery percentages. It'll take a few days / charge cycles to cure it if it will work at all.
I'm betting the reboot on network swapping is not related. Does it happen when the network automatically switches? Or when you physically change it from GSM to 3G?
Either way it sounds like something is either screwy with the ROM or the radio.
I'd try reflashing the 3.32 firmware with the radio again. AND ONLY THE 3.32 RADIO AND FIRMWARE, NOT THE 3.12 FIRMWARE HACK THAT HAS BEEN SUGGESTED. Maybe something got wacky when you put it on the first time. That will let you keep the ROM and settings in tact.
If that doesn't work, try reflashing the ROM and see if there's a glitch from a borked install.