Why am I seeing blank song tracks?

This issue is a bit hard to explain; I'll try to keep it succinct. I see this only when I play music in my car. I have an iPod shuffle (latest version) and plug it into a USB port in my car. The iPod works fine, but in a few places as I scroll through my song list, a series of blank tracks come up. It scrolls automatically through the tracks and I hear clicking noises. Sometimes the voice-over comes on and announces each track, which appears on my car's audio screen as sn01, sn02, etc. with "unknown artist" and "unknown album" underneath the track number. I also notice that when the next song comes on, I can't scroll backwards - it's like those blank tracks lock it so I can only scroll forward. I don't know if it's an iPod issue or a car audio issue. I don't see any blank tracks in my iTunes account. It appears that the iPod syncs fine.

Anyone experience this?