using tdbimage with sql serveur ?

I was using in interbase server a blob file
with delphi tdbimage it was working very well

now i try to do same thing with SQL Serveur 6.5

and when delphi post my data with the fiel image empty
delphi don't put the field at null so i have this error

Erreur SQL gnrale
Must attach a value to the binary prefix 'Ox'; zero-length binary value is
not allowed

thank you to give me an help