[Dxbase] unauthorized callsign error

[KG8DH at aol.com]

Hello,
I'm trying to modify the database to input the proper callsign I used when 
making q's about 10 years ago.  When I attempt to change the call in the opr 
callsign column, I get the error "unauthorized callsign".  I've looked in the 
help file a little bit and can't find the answer.  I don't have multiple 
callsigns, just old ones that changed as I upgraded license classes.

Thanks
Geary
KG8DH