I just ripped Tom Petty,, Full Moon Fever to WMA on CD-r and it worked fine in the Navi stereo in my Civic. Make sure you set it to rip for portable devices. I used 128Kbps compression.

I must say the whole windblows media play interface sucks. I use CDex for riping my mp3's. Simple, fast and to the point. Not mental masterbation like the windblows junk.

Good luck