I had a similar problem with data CD's burnt in MC.
I could play them on my home DVD player but navigating to the tracks I wanted to play was difficult. The directory structure was a folder for each album. Once I'd played a track in an album folder I couldn't go back up a level to the CD directory level.
Burning the same CD's with Nero 5.5 solved the problem. Maybe something in the way MC writes data CD's which isn't very compatible with a lot of mp3/dvd players?
Media Center Registered 9.1.232 -- C:\Program Files\J River\Media Center\
Microsoft Windows XP Workstation 5.1 Service Pack 1 (Build 2600)
AMD Athlon 1403 MHz MMX / Memory: Total - 785 MB, Free - 463 MB
Internet Explorer: 6.0.2800.1106 / ComCtl32.dll: 5.82 (xpsp1.020828-1920) / Shlwapi.dll: 6.00.2800.1106 (xpsp1.020828-1920) / Shell32.dll: 6.00.2800.1233 (xpsp2.030604-1804) / wnaspi32.dll: 4.71 (0002) , ASPI for Win32 DLL, Copyright © 1989-2002 Adaptec, Inc. / Aspi32.sys: 4.71 (0002)
Ripping / Drive E: Copy mode:ModeBurstBigBuffer CD Type:Auto Read speed:Max
Drive F: Copy mode:ModeSecure CD Type:Auto Read speed:Max
Drive G: Copy mode:ModeBurstBigBuffer CD Type:Auto Read speed:Max
Digital playback: Yes / Use YADB: Yes / Get cover art: Yes / Calc replay gain: Yes / Copy volume: 32767
Eject after ripping: No / Play sound after ripping: No
Burning / Drive F: CD-RW CDR-6S48 Addr: 1:1:0 Speed:24 MaxSpeed:48 BurnProof:Yes
Test mode: No / Eject after writing: Yes / Direct decoding: Yes / Write CD-Text: Yes
Use playback settings: No / Normalization: None