Make sure you burn them right. You probably use some sort of program so you really don't have to worry about it. The burning must be closed for the disc to work. CD-RWs don't work in many HUs, so make sure they're CD-Rs. They could have just used a crappier HU that wasn't as new. My mom's civic's HU plays CD-Rs, it might even play some CD-RWs.

"Wow, that sank fast." "Yeah, like a rock."
96 Contour GL ATX
9mm Ford Racing Wires; 2 Resonators down, 1 to go;"Special airbox"; many mods planned
Sony CD player: 50wattsx4;remote;
Speakers=50 watt Pioneer 6x8s
Ross Evans smile