I had the same exact issue, rooted with not recovery. Received the update several times, phone rebooted, got about 40% through the update process, rebooted again and didn't actually install anything.
Checking the version number was still on D80110c.
My wife's g2 unrooted upadated fine.
I used the LG support tool, took about 1/2 hour and all is well.
download it here:
or you can pull it from my copy account:
oh and if you're not familiar with copy. . .like dropbox, but 20 GB free, 5GB for each referral
here's my referral:
i did lose root, but that was easy to get back: