how to configure: The Remote Agent Utility

Hi, now I have this error after the backup.
Final error: 0xe0001403 - The logon account specified in the Remote Agent Utility cannot be authenticated. Update the entry in the list of authentication credentials on the media server.
Final error category: Resource Errors

Again, I have this error.
(Job: "SVR-06 - 1. Daily Full Backup") SVR-06 - 1. Daily Full Backup -- The job failed with the following error: The logon account specified in the Remote Agent Utility cannot be authenticated. Update the entry in the list of authentication credentials on the media server.

I entered the sys user but without success. What kind of user they want ?

And here is the whole output of this job:

 # -----------------------------------------------------------------
 # RMAN command section
 # -----------------------------------------------------------------
 
 RUN {
 ALLOCATE CHANNEL ch0
     TYPE 'SBT_TAPE';
 SEND 'BSA_SERVICE_HOST=198.64.197.10,NBBSA_TOTAL_STREAMS=1,NBBSA_JOB_COOKIE={469AC92C-02E6-41DB-BC07-7CA890F63B94},NBBSA_DB_DEVICE_NAME=Oracle-Win::\\MENPET-SVR-06\orcl';
 BACKUP
     INCREMENTAL LEVEL=0
     FORMAT 'BE_U'
     DATABASE FORCE PLUS ARCHIVELOG FORCE NOT BACKED UP;
 BACKUP CURRENT CONTROLFILE
     FORMAT 'BE_U';
 
 RELEASE CHANNEL ch0;
 }
 
connected to target database: ORCL (DBID=1151191104)

using target database control file instead of recovery catalog
allocated channel: ch0
channel ch0: sid=136 devtype=SBT_TAPE
channel ch0: Symantec/BackupExec/1.1.0

sent command to channel: ch0


Starting backup at 28-OCT-09
current log archived
channel ch0: starting archive log backupset
channel ch0: specifying archive log(s) in backup set
input archive log thread=1 sequence=1175 recid=1 stamp=700159552
input archive log thread=1 sequence=1176 recid=2 stamp=700217643
input archive log thread=1 sequence=1177 recid=3 stamp=700228598
input archive log thread=1 sequence=1178 recid=4 stamp=700237166
input archive log thread=1 sequence=1179 recid=5 stamp=700322405
input archive log thread=1 sequence=1180 recid=6 stamp=700422653
input archive log thread=1 sequence=1181 recid=7 stamp=700473674
input archive log thread=1 sequence=1182 recid=8 stamp=700561873
input archive log thread=1 sequence=1183 recid=9 stamp=700660833
input archive log thread=1 sequence=1184 recid=10 stamp=700732874
input archive log thread=1 sequence=1185 recid=11 stamp=700744805
input archive log thread=1 sequence=1186 recid=12 stamp=700783224
input archive log thread=1 sequence=1187 recid=13 stamp=700795750
input archive log thread=1 sequence=1188 recid=14 stamp=700827873
input archive log thread=1 sequence=1189 recid=15 stamp=700830070
input archive log thread=1 sequence=1190 recid=16 stamp=700830403
input archive log thread=1 sequence=1191 recid=17 stamp=700830764
input archive log thread=1 sequence=1192 recid=18 stamp=700831061
input archive log thread=1 sequence=1193 recid=19 stamp=700853213
input archive log thread=1 sequence=1194 recid=20 stamp=700873209
input archive log thread=1 sequence=1195 recid=21 stamp=700882522
input archive log thread=1 sequence=1196 recid=22 stamp=700943012
input archive log thread=1 sequence=1197 recid=23 stamp=700969027
input archive log thread=1 sequence=1198 recid=24 stamp=701021126
input archive log thread=1 sequence=1199 recid=25 stamp=701051990
input archive log thread=1 sequence=1200 recid=26 stamp=701084617
input archive log thread=1 sequence=1201 recid=27 stamp=701141760
input archive log thread=1 sequence=1202 recid=28 stamp=701190424
input archive log thread=1 sequence=1203 recid=29 stamp=701253681
input archive log thread=1 sequence=1204 recid=30 stamp=701301613
input archive log thread=1 sequence=1205 recid=31 stamp=701314520
input archive log thread=1 sequence=1206 recid=32 stamp=701375826
input archive log thread=1 sequence=1207 recid=33 stamp=701389223
input archive log thread=1 sequence=1208 recid=34 stamp=701401036
input archive log thread=1 sequence=1209 recid=35 stamp=701453269
channel ch0: starting piece 1 at 28-OCT-09
released channel: ch0
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup plus archivelog command at 10/28/2009 16:07:53
ORA-19506: failed to create sequential file, name="BE_0gksukun_1_1", parms=""
ORA-27028: skgfqcre: sbtbackup returned error
ORA-19511: Error received from media manager layer, error text:
   BEError(0xe0001403) The logon account specified in the Remote Agent Utility cannot be authenticated. Update the entry in the list of authentication credentials on the media server.



Recovery Manager complete.