VB /Large Binaries Fields/BLOB

I have the problem of inserting large binary data in a field of an Informix DB defined as type byte (BLOB), from a VB app. with ODBC. I have access to the DB and can insert,delete, update, etc all the fields in every row except the ones defined as byte in the DB. Has anyone else had this problem? Any kind of help is greatly appreciated. TIA Paco Garcia pgarcia@cam.es