My new Flip Ultra HD shoots HiDef MP4 files that are not recognized as AVCHD by AVCHD Upshift. Any suggestions on a program that can conver the videos to another file format for easier effort and still retain them at HD resolution?

Any feedback on this would be appreciated. There is a Flip Video converter available, but I don't know if it will convert it to a HiDef AVI or MOV.