i'm not sure but try one of those:
1) try to convert that IP to a string with a variable and use that upping your data
Dim myIP as string = Ctype("20.20.30.1",String)
INSERT INTO StaticIPAdd (IPaddress ,IPOwner)
VALUES (myIP, 'A description of carlos machine.')
2) if u are using SQL Server go to
table design and set option identity to NO
As said, i'm not very sure about this but it could be...