Here are the steps that I took to remedy my problem:
- Ensure all the files are MP3 and not AAC (You can convert them inside iTunes).
- Create an empty folder on your desktop.
- Drag the MP3 songs that you want from the Music Library to the new folder on your desktop
- Once all the songs you want are in that folder, Plug in your Sansa
- Now open up the Sansa in My Computer (should show up as a removable drive) and go into the Music directory
- Remove any songs you don't want
- Drag (or copy&paste) all the songs from your folder on the desktop to your Music directory on your Sansa
Hopefully, this helped you!