I was thinking battery as well but there appears to be no external signs of damage. It is an older phone so the battery could certainly be failing. Every setting is stock. She claims it is on every call. At this point I think I am going to flash the gingerbread based GeeWiz this weekend and see what happens if that resolves anything.
I don't know how deep you want to dig into this since it's a friend's phone (and they probably expect to be able to use it), but if you'd like I can build a version of the audio module for this version of the ROM like I did here:
http://xdaforums.com/showpost.php?p=36748252&postcount=31
It's not hard for me to do, actually it takes about 10 minutes from start to finish, including making the rollback patch, but you'd need access to the phone to run ADB and capture the events during the course of the problem and be able to examine them.
Or ... if I made the patch and it was installed, you guys could send me a Bug Report on it as well (Settings/Developer Options/Take Bug Report). This includes a LOT of information, I cannot guarantee that nothing personal is in there, but there really shouldn't be. Heck, you could have her do that now if you want, perhaps the answer is already in there! If you do want to take a bug report, what will happen is a whole lot of nothing, or so it will seem, for about 3-5 minutes. You'll probably see a few "shell has been granted root permissions" pop-ups, but otherwise the phone makes a tone, gets real slow for a few minutes, and ultimately pops up in GMail with a draft message. By default, it will send to yourself, just forward it to ... well ... I'll PM ya. You can probably figure out my gmail address if you think REALLY HARD about it - LOL. Perhaps djp952@?
Let me know what you think, I'm happy to make the patch to enable the extra logging, but only if you want to use it. I cannot guarantee that it would reveal the issue, I'm hoping more for a clue
I'm beginning to wonder if the "fix" I did in GeeWiz 3.3.1 to address a possible but extremely unlikely condition with in-call audio was ill-conceived for some reason. I reviewed it again and it looks OK, but I'm thinking this has to be my fault somehow ... too weird to not be!