Backup omits the disk storage pool.

Hi everybody,
I have "Storage Management Server for AIX-RS/6000 - Version 5, Release 1, Level 
8.0"
Right after I upgraded to this version strange things started happening to the 
server.
Before I had disk buffer 8Gb and all backups were good. All backup usually 
completed before 6 or 7 am.
Now I have plenty backups completed around noon and even later. If I do "q se 
f=d" I see a loot of sessions waiting a mount point. Looks like it happening 
right when migration is triggered first time in the night. So I increased the 
disk pool  up to 24Gb ( that is all I have now) and now it looks like follows:
WRKDISK      DISK          24,610.0   26.4   26.0    70    5  WRKPOOL

The strange thing here is when migration starts it never ends. The same volumes 
is requested by nodes and is used for both migration and backup, means backup 
goes through migration process. Look what gives me "q pr" command:

   1,812 Migration            Disk Storage Pool WRKDISK, Moved Files: 96162,
                               Moved Bytes: 22,031,622,144, Unreadable Files:
                               0, Unreadable Bytes: 0. Current Physical File
                               (bytes): 87,867,392
Current output volume:
                               787ABP.

   1,813 Migration            Disk Storage Pool WRKDISK, Moved Files: 104037,
                               Moved Bytes: 23,340,695,552, Unreadable Files:
                               0, Unreadable Bytes: 0. Current Physical File
                               (bytes): 12,288
Waiting for mount of output
                               volume 798ABP (95 seconds).

   1,814 Migration            Disk Storage Pool WRKDISK, Moved Files: 91987,
                               Moved Bytes: 22,099,623,936, Unreadable Files:
                               0, Unreadable Bytes: 0. Current Physical File
                               (bytes): 2,351,595,520
Current output volume:
                               799ABP.

   1,815 Migration            Disk Storage Pool WRKDISK, Moved Files: 109809,
                               Moved Bytes: 21,499,760,640, Unreadable Files:
                               0, Unreadable Bytes: 0. Current Physical File
                               (bytes): 12,288
Waiting for mount of output
                               volume 880ABP (35 seconds).

---------------------------

Pay attention to the "Moved Bytes". It is 22G on every drive. Maximum backup 
size may not exceed 1g per PC and usually 200-300 Mb. But I have about 500 PCs.


Am I the only one who has this problem?
 If you know how to fix it please share your experience.
I want nodes do not reserve the tapes but keep backup going to diskpool and let 
migration move the data to the tapes.

Yuriy Us.