ultrium 448 on esx 2.5.3 with adaptec scsi card resets

[NXS]

I have a DL380 G4 (latest FW) with 2 xeon processors in HT with 5 disk in raid5 connected with an adaptec 29160 (PCI slot 133 MHz) Ultrium 448 (latest FW)
When I do some single vmdk test file backups from the console 1 get from tar 2,30 minutes for a 5 GB file and 10,50 minutes for a 16 GB file
from DP 5.5 i get 1.30 minutes for the 5 GB file and 8 minutes for the 16 GB file. But when I try to d a full backup from the console and put the VM in hot mode I is getting really slow.
A network copy from the server to a laptop from about 600 MB takes 30 seconds and between VM 's is around 20 seconds and between different ESX VM's it is also around 30 seconds. When I try to backup a windows VM from the console It is very slow (10 GB in 20 minutes). I checked the speed of the console with cat /proc (1GB FD).
Also the indexing of the data disk 120 GB of a windows 2003 VM takes very long. After 20 minutes he only indexed 40 GB.
I also tried to put the the tape direct into a new VM that works. But is also slow.

Whe I start the backup the backup craches after 2 hours with this message in the log files.

vmkernel: 0:01:02:21.595 cpu0)SCSI: 782: INQUIRY request with EVDP set
Jul 7 22:55:09 srembesx03 vmkernel: (scsi0:A:5:0): 0:03:55:34.699 cpu3)Unexpected busfree in Command phase
Jul 7 22:55:09 srembesx03 vmkernel: SEQADDR == 0x17a
Jul 7 22:55:10 srembesx03 vmkernel: 0:03:55:35.571 cpu3)WARNING: SCSI: 5452: None of the paths to target
vmhba1:5:0 are working.
Jul 7 22:55:12 srembesx03 vmkernel: scsi0:A:5:0: 0:03:55:37.362 cpu1)DV failed to configure device. Please file
a bug report against this driver.
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu3)SCSI: 2791: Reset requested on handle 375 (1
commands)
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)SCSI: 2983: Reset on handle 375 [0/0]
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)SCSI: 2612: handle 375/375: 1 outstanding commands
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)LinSCSI: 3487: start
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)scsi0:0:5:0: Attempting to queue a TARGET RESET
Jul 7 23:35:13 srembesx03 vmkernel: CDB:
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)scsi0:0:5:0: Command not found
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)aic7xxx_dev_reset returns 0x2002
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)LinSCSI: 3543: done, retval 0x0
Jul 7 23:35:13 srembesx03 vmkernel: 0:04:35:38.321 cpu1)SCSI: 2840: Completing reset on handle 375 (0
outstanding commands)
Jul 7 23:35:17 srembesx03 vmkernel: (scsi0:A:5): 160.000MB/s transfers (80.000MHz DT, offset 64, 16bit)
Jul 8 05:09:02 srembesx03 vmkernel: 0:10:09:26.228 cpu0)SCSI: 782: INQUIRY request with EVDP set