Hey man thanks for all the hard work. Just bought you app tonight in hopes of having the Epic4g working 100% in the future. Rooted with noobl's 1.30 kernel and the stock busybox that titanium backup installs (1.16.0) your app does not work.
How ever when I installed BusyBox from the market and it updated my busybox to version 1.17.0 your application just nukes the signal/radio when I hit the Roam Only button. I lost all radio signal completely. I can not really duplicate this bug though. I rebooted a few times and now I can freely switch between Roam and Automatic with out rebooting.
Heh at any rate cheers for making this app man, I appreciate it.
(BTW all this occured with me running the latest Epic4g update DI07)
Edit: This was with v1.1
Hopefully v1.2 will work for you. No one should need to mess around with this stuff, the whole idea is the app should just work.

Same error message for me.