Outlook Syncing Client Has Stopped working

My mom has been trying to sync her phone to the iTunes, but it keeps saying "Outlook Syncing Client has stopped working" whenever she gets to the calendar syncing. And only the calendar syncing.

Outlook is a 2003 version, and had been working prior to the itunes update.

iTunes is up to date.

When I do it on my computer, it doesn't have the problem. However, I have not updated the iTunes on my computer.

Any suggestions? I tried turning off all other Add-ins on the Outlook other than iTunes. It has also disrupted some of her appointments. And on some cases, older entries show up, but with no dot on the date.

Both computers are Windows Vista.