CyanogenMod 10.1

So here's the deal. I have an AT&T Samsung Galaxy S3 and I was super stoked when they started releasing CyanogenMod 10.1 nightlies for the device a few days ago, having ran CyanogenMod 10 since day one of having the device. It actually runs very well, with very few bugs that I've noticed, but there is one thing: my HSPA radio will not work. It resorts to good ol' 3G, but it's actually a lot slower and I just can't hang with it. I switched to my CyanogenMod 10 backup to see if the device was affected on other ROMs, and what do you know, the 4G (I know, I know, not true 4G) worked. Can any of you offer some insight to why this wouldn't be working? Should I just chalk it up to a bug that will eventually be fixed or is there something I can go in and mess around with to get it working again? I'm fairly desperate (hope that doesn't sound too sad) here so any advice would be greatly appreciated. You guys are the best!

Also I should note that I don't live in an LTE area so I can't say if that's affected as well.