i tried deselecting "include voice memo". that didn't work. i then tried deselecting "include music video" and "automatically fill free space with songs". that did the trick, which is odd since i don't have any music videos on my iTouch.
I found the following webpage / advice validated my own findings:
http://www.technipages.com/iphone-3gs-error-the-ipod-cannot-be-synced-an-unknown -error-occurred-13019.html
Now try to sync your iPhone and see if it works. If it does, there is obviously a problem with your Voice Memos. Email them to yourself from the iPhone using the Share option so that you don’t lose any data. You can then delete the Voice Memos from the iPhone and iTunes.
This problem can also be caused by corrupt music, applications, podcasts, etc. You may need to track down which type is causing the issue by disabling each data type to see which one is causing the issue.