After having to ask what turned out to be an embarrassing question (by the way . . . I fumbled upon the setting and fixed the problem, but couldn't get back to the forum to delete the posting -- thanks for the help, anyway) I am certainly not the person to ask about the f-fwd of mp3's.
I do have one other question though --- how can I adjust the volume of the navigation voices when they interrupt? Compared to the music volume (regardless of source playing) the nav voice volume is really high!
I looked through the owner's manual, but couldn't find anything about this.
This is only my second day with the 8120, but it's great . .. Alpine R-series coaxials, Memphis MCA-3004 amp, Alpine overhead monitor (and duplicate DVD player . . couldn't find a monitor I liked better) and finally, the Boyo VTL-200 back-up cam. I'm happy!