Listing problems

Please, Please, Help me. I have been listing since last year and never had a problem until last Tuesday. Every time I list a item and go thru the whole thing, I get a notice saying "cannot open used default data base using master data base instead." Now I dont even know what a "default or "data base is". So I am at a lost as to how and get this corrected. Gun Broker's reply was basically nothing. I really need some help.
Will some one email me if they know how to correct this?
Regards, Jerry
gbb@i-55.com
985-643-9916