I had a problem with a particular album playing tracks in the wrong order off an SD card recently. There's been a lot of talk on here about the RCD unit reading the files property info so I checked that and everything was fine. The album also played correctly on my PC.
After much head scratching I added the track numbers in front of the track file names 01 - 02 etc and this fixed the problem. The RCD 510 seems to filter this part of the track name out so it doesn't get shown in the display (or maybe it gets the track name from the files properties
)All is now well and maybe this helps anyone else who's seen the same problem.