[Koha] Barcode help

I am still trying to get some barcode stuff to work. We have koha installed on Ubuntu 6.06 and up and running. I am trying to move the library database over but there is problems with using the barcodes we already have on the books. I scan the books in and have them looked up on the Z39.50 server and all the info comes up. The problem comes in when I try to scan in the barcode on the book for reserves it will not accept it. Koha wants to autogenerate one. I turned off autogenerate on under system preferences and catalogue but it still refuses to let me input a barcode. Can any one help with this problem?