Thanks for the replies. I was able to burn a disc with the .txt, .md5 and .jpg coverart to the root using RainDawg's method. The disc then played fine with WinDVD on the computer but failed when I tried it in my Sony DVD player. I got the 'no disc' error.

Until I "upgrade" my standalone DVD player to one the plays a wider range of discs (my Sony DVD player plays all DVD-R and DVD+R I've tried but won't play a single CDR), I will continue to burn standard discs (without the extra files) and save the extras on the HD for seeding.