I had a JVC KD-R606 head unit installed in my car a couple of weeks ago to use with my iPhone 3GS. The box was marked "iPhone ready".
I was initially impressed with how perfectly it worked with my iPhone. That was until today. The iPhone has been working fine in my car with about 500 songs on it. I installed another 10 today. Now when I plug my iPhone in, the JVC unit pops up with "CANNOT PLAY".
I removed the new songs. Still no go, so I removed all songs except for a few purchased through iTunes. Still no go! Arghhhh!
My wife's iPhone still works perfectly with the JVC unit.

The manual says that this error will appear if the songs are in the wrong format, or there are no songs detected. I have also heard it will appear if the song names or folders are too long. But I have removed everything! The only songs left are iTunes songs, and they have definitely played ok before.
Does anyone know, if you remove music of your iPhone, by un-selecting a Playlist. Is the music actually removed or are the references to it just removed. I'm wondering if the JVC unit is still seeing the new songs I put on it, even though the iPhone can no longer see them???
Anyone have any other ideas, this is really pissing me off... it will be going back to the shop if I can't find a solution.
Cheers
Rayden