Calendar has dots on every day when there's no events

Hi. I have a problem that has resulted in a dot appearing on every day of my calendar on my iPhone.

I recently updated my iPhone to OS3.0. I have not had a problem with Calendar, nor did I after the upgrade...UNTIL I subscribed to the Birthday calendar that iCal (on my Mac) automatically creates from the Address Book. Being able to subscribe to calendars on the iPhone is new with OS3.0 and so I was very happy to see it available. On my Mac (running Leopard), I published my Birthdays calendar on MobileMe (which I have a family subscription for), sent the email to myself and subscribed on my iPhone. The Birthday calendar is now there, but every day in Month view shows a dot to indicate an event, but there are no events on the majority of these days (it says No Events in grey under the month view when I click on each day).

Whilst in Calendar on my iPhone, if I go back and turn off the Birthday calendar and leave the other calendars on, all the dots disappear. So it seems to be a fault in the Birthdays calendar.

And to make it more mysterious, I have set the same thing up for my partner (using his iCal on his profile on the same Mac which has the same timezone settings and other settings) and his has synced perfectly without putting dots on every day.

Any suggestions?