Staging fails with message: nsrmmd #133: Read operation failed and aborted

Hi,

We have Networker 7.2.2 Update1 under Solaris 8. Last night, the staging has aborted with following errors and the disk is nearly full.
The volume disk is mounted properly and in fact the backup to disk has been succesfully, but the staging (automatic or manually) does not work.
The destination tape also is mounted.
We have rebooted the server with the same results.

Have anybody any sugerence?
Thanks very much.
JM

05/23/07 22:18:18 nsrmmd #133: Read operation failed and aborted.
05/23/07 22:18:18 nsrmmd #133: Read operation failed and aborted.
05/23/07 22:18:19 nsrd: ejsun33:cloning session done saving to pool 'Diario' (Diario.124)
05/23/07 22:18:19 nsrd: cl_none:ss_none done reading from Diario.Disco.1.RO
05/23/07 22:18:19 nsrd: media info: restarting nsrmmd #133 on ejsun33 in 2 minute(s)
05/23/07 22:18:19 ansrd: ansrd_clone FAILED: errnum is 25004 and errstr is RPC receive operation failed. A network connection could not be established with the host.
05/23/07 22:18:19 ansrd: failed to execute MODE_CLONE
nsrstage: RPC error: RPC receive operation failed. A network connection could not be established with the host.
nsrstage: Cannot open nsrstage session with ejsun33
nsrstage: Failed to clone the following save sets:
2873746824
3242764869
3125409178
2336538742
3544497945
3309531501
.....
.....