I havent heard anything like that.
Hence just think of the people hosting challlenge lobbies (the ones that put the patch on then update that ps3 not the transfer cable way)
They dont get banned/caught.
But if your not sure, delete backup manager or anything else you got but leave ps3ftp, then startup filezilla and log into your ps3, look for the ftp12345 folder and get rid of that, and also the folder launch123 (or wateva its called... which is what the original backup manager left)
But i honestly dont think you need to go to that extent. Its only if you were online (which u cant right now) playing a backed up game that u did with the original backup manager and not with the stealth one.
other then that your safe as