maxdb backup incrementale

hello

i ve tried to make backup incremental on maxdb 7.7.07 database and it fails i use

medium_put inc /home1/SAPDB/sapdb_backup/KRLIVE/inc FILE PAGES

db_admin

db_connect

backup_start inc

the backup finish with success but the restore print me -111 error incompatible medium and when i disable the logging the restore finish with success and nothing happen.