FANCY: well, you may or may not already know this, but your problem lies here, i believe.
first:
you have to mix everything down to tracks 1&2... because only these tracks are burned to the cd. (one left, one right) so if your song was on 7&8, or something else, then that's why it was blank... also, as mentioned above, this problem would've been solved by mastering the track cuz it makes a new song with everything on 1&2. (doesn't have to be mastered though)
secondly:
once you've done that, then you have to copy and paste tracks 1&2 on top of itself... check your manual, but basically you paste them starting 00:00:00 to the end point, say 04:33:00... that tells the vf80 that that is where your song is...
thricely:
and then delete everything after 04:33:00 to make sure that there's no excess stuff after where the song should end.
so now you should have your entire song on tracks 1&2 and have them between 00:00:00 and 04:33:00... once you burn that, it should come out fine. that's how it says to do it in the manual.. but if i'm wrong lemme know cuz i'm saying that from memory.
later
-dan