I just installed the latest version of FTBLite2 and found the radio
after finding a way to add tune cards. I added my station and reloaded Minecraft...
and nothing. so had a look into config file and the file had reset.
I can get the file to work as long as its in read-only

I also experienced a reset of the configs on the Direwolf20 pack, but it was after editing the colors for the default stations without adding new stations.

Copying a backup of the config (with changes) caused a crash that terminated the client totally. Commenting out stations led me to find a spelling error on the color code in my case (Pruple =/= Purple). Do you have a backup of your config file with the additional stations?

Doesn't look like our problem. It's probably launcher that restores default configs on every startup. Will reopen if new information shows.