Where are Automatic alerts for Birthdays coming from?

Hi there,

I upgraded my wife's MacBook Pro and my machines to Lion shortly after it was released. Now my wife gets alerts from iCal for every Birthday she has in here Birthday calendar (always at 8 am on the specific day, with sound "Basso"). I thought that's a nice addition to iCal in Lion. BUT, it's only on here machine, not on mine.

Even if I enter a new birthday to a contact in her Address Book it immediately get's an alert attached.

And I find no settings for this in iCal or somewhere else. So, now I'm wondering where these alarms are coming from. Some Add-on, some script? I have no idea (she has nothing installed on her own on her MBPro). Any ideas?

Edit: well, just now I realized that I have these Birthday alerts on my iMac (but they never popped up - maybe because I'm at work anly at 9), but they are not on my MacBook Pro.