We have just reciently deployed Exchange calendar as the prefered solution to our users corporate wide. We are now seeing a lot of the users starting to have an issue with the calendar in regards to accepting or declining meetings. What happens is that the accept and decline buttons become greyed out. The majority of the users with this issue are using Entourage, but I have a couple that are using Outlook. Another interesting fact that I have found is that, the users were not having an issue with their calendars until they set up a deligate for their account. We have attempted to remove the delegate, but that has not helped the situation. I have done quite a bit of research online, and most people attribute the problem to permission's being incorrectly set on the account. But no one has given a good way to reset a user's Exchange calendar or how to fix the issue. Is there a way to set a user's account back to default settings and permissions?