Again, it's been a long time since I've done this, but no one has said yet whether or not it will work.

Start up iTunes, but don't load anything at all into it. Attach your iPod. Select the iPod within iTunes. Find the files you want to put on your iPod on your hard drive. Select them. Drag them directly to your iPod within iTunes.

When I used to do this, it completely bypassed the iTunes library and just put the tracks onto the iPod.