Help with FMP Unlimited and IIS

[koronias]

I have written a database that I am hosting with FMP 5 Unlimited and IIS 4.0 on an Windows NT 4.0 server. Users are authenticated using NTFS security and authentication occurs without a problem. They can create records but every time they attempt to edit a record, they get a null pointer exception error. If they refresh, they receive a prompt telling that that they must reconnect, they click okay and the record is edited. They don't have to log back in, it simply reconnects and edits the record. Does anyone have any idea as to what may be causing this error? Please help!!!