My heart just skipped ten beats.
It all started when I attempted to backup my contacts from the iPhone onto my work computer. I didn’t check the box that reads “put new contacts created on this iPhone into the group:”. As a consequence, all my phone contacts got mixed in with business contacts, which turned into a real mess. So I deleted all my phone contacts from the address book and mistakenly hit sync. Big mistake. In a matter of seconds my phone was free of all contacts!
I managed to undue the delete in address book and get my phone contacts organized into a group. However, now whenever I hit the sync button I kept getting an error message from iTunes that the iPhone has disconnected and the sync hadn’t been successful. Oh crap! Was I really going to have to hand enter hundreds of phone numbers, emails and addresses - again?
I googled for a little while but wasn’t able to find a solution. Until I stumbled across a mac forums post from several months ago. One of the users suggested doing the following:
This worked for me: Go to Applications > iSync > Preferences > Reset Sync History
I followed these steps and was back in business. I have posted this here to save others the same headache. Thanks ryanjbonnell.