I am using Google's exchange service on my iPhone, and I have successfully selected which calendars I want to sync by going to m.google.com or whatever the Sync address is. However, in the native iPhone app, I have this weird calendar called "Birthdays" in the "Other Calendars" section. I have no idea where this calendar is coming from - its not in Outlook (and I don't sync with Outlook anyway), and its not my Google Birthday calendar (the dates are wrong). How do I remove it? I'm using an iPhone 3GS with iOS 4.1.