iPad calendar not sending updates

Hi there,

I am trying to update an event that has already been accepted by an invitee, but the updated details do not get send to the invitee.

The invitee is my wife so we also have her calendar on the iPad but she also has her own iPhone 4S. Both devices have my Apple ID on and access to my calendar (as well as her calendar) - could that be the problem? It wasn't a problem when the initial invite was sent.

Is anyone else having this problem?

Thanks