SM2T Restore fails with "Data operation halted due to unrecoverable internal NDMP Server error. (4044524)

The SM2T 3TB restore runs for a long period an then after many hours later the restore fails with the following error:

'Data operation halted due to unrecoverable internal NDMP Server error'

The restore request shows that the correct Media Block Size (MBS) was used for SM2T (this is the only MBS that can be used for SM2T):

Job Message 2011/04/07 14:32:40 520 Data Plugin inc9206 Restore Request

With sub text...
Restore Environment:

NDMP_VERSION = 4
DATA_BLOCK_SIZE = 240
FILESYSTEM = /vol/stv9201_appl01
SMTAPE_DELETE_SNAPSHOT = Y
TAPE_NAME = nrst4a
TYPE = smtape
DIRECT = N

Restore Paths

Original Path =
Destination Directory = /vol/test
New Name =
Other Name =
Node = 18446744073709551615
FhInfo = 18446744073709551615

And eventually see the following errors:

Information 2011/04/07 17:42:37 520 Data Plugin inc9206 NDMP: NORMAL 0: SMTAPE: Bad block in read stream. vbn = 1598836319, max_vbn =

1252465776
Error 2011/04/07 17:42:37 520 Data Plugin inc9206 Data operation halted due to unrecoverable internal NDMP server error