hello, i need help please

i execute the next line: su amanda -c "/usr/sbin/amlabel respaldo EtiquetaDisco01 slot 1"

have the next problem:

chown(/var/log/amanda/server/amlabel.20090514191033.debug, 34, 34) failed. <Operation not permitted>amlabel: could not load slot "1": chg-multi: slot is empty


in my log the message:

amlabel: debug 1 pid 3477 ruid 1000 euid 1000: start at Thu May 14 19:03:58 2009
chown(/var/log/amanda/server/respaldo/amlabel.20090514190358.debug, 34, 34) failed. <Operation not permitted>amlabel: debug 1 pid 3477 ruid 1000 euid 1000: $
changer: got exit: 1 str: 1 chg-multi: slot is empty
amlabel: time 0.042: could not load slot "1": chg-multi: slot is empty
amlabel: time 0.042: pid 3477 finish time Thu May 14 19:03:58 2009

thanks..