Outlook 2003 - Exchange 2003 - error messages

[popinss]

Hello,

Could someone help me to solve the problem I meet :

I receive these two messages when I try to add something to my calendar :

"The custom form could not be opened. Outlook will use an Outlook form
instead. An error occurred registering the form in the OLE registry."

"The reminder for "xxx" will not appear because the item is not in your
calendar or task folder. Is this OK ?"

How can I add something into the calendar ?

Thanks