Well, after several failed uninstall and reinstall of rocketbox I've finally, just now, completely uninstalled everything and did a complete installation including the bootloader. Forward and backward is working properly although I lost all music files due to the reformats (have backups). Was a pain going through this to get the two functions to work but it's working now so no biggie.
The uninstall/install of Rocketbox produced the same issue even at default settings. Somehow, installing with the bootloader again changed it as I see nothing else that is different.