Can't sync playlist to new iPod Touch

Hello,
I have a 32GB 4th generation iPod. I have 300+songs on it. Sync's great every time. I purchased an 8GB 3rd generation. I want to move one music playlist to the 8GB but iTunes will only move 64 of the 300. I get the warning/error message that iTunes can't sync 100+songs because it can't find them. How can it find them for the 32GB but not he 8GB? I'm on Windows XP. Tried many things. If anyone has a step by step for me that would be great.