Audio Systems: CD Compatibility, portable cd player, computer player

Question
I burned a CD from a cassette for someone locally, using a computer DVD/CD burner (LiteOn brand).  I used Nero software, and selected "audio" CD.  He got an "error" on a DVD/CD machine, and the CD skipped or sometimes didn't play to the end on portable machines.  On my computer player and the burner, as well as a newer portable CD player, it played perfectly.  On an older (11-12 year) portable
CD, it wouldn't play.  Are CD's coded differently now, or is there something else going on?  I am not sure of the age of his machines.  THANKS!

Answer
burned cds are actually quite different than the cds you buy prerecorded.  there are different quatilies of the surface of the disk so maybe the disk he used was kinda cheap.  there's also alot of settings in nero that have to be right for the cd to play correctly.  Usually when I burn a cd I pick:
No multisession
Yes to finalize the cd
Disk at once (NOT track at once)
also choose a lowwer burn speed.  if his burner supports high speeds like 52x use something like 16x,  if it only goes up to 16x then choose 4x or as low as it can go.
That should make a good cd that will play in just about everything.  
Good luck!