iPhone sync - unknown error 13019

Just in the last 2 days I started getting an error message everytime that I sync my original iPhone.

"The iPhone cannot be synced. An unknown error occurred (13019)."

Anyone have any ideas? It seems like it is syncing as far as I can tell even though I'm getting this error. The online help says to reinstall iTunes but that makes me a little nervous. I've never had a problem with iTunes or my iPhone before & I do not want to lose any data/settings.