1-2 times a day I am getting this:

mptscsih: ioc0: >> Attempting task abort! (sc=ca18c800)
mptbase: Initiating ioc0 recovery
mptscsih: ioc0: >> Attempting bus reset! (sc=ca18c800)
mptscsih: ioc0: >> Attempting task abort! (sc=e9611b00)
mptbase: Initiating ioc0 recovery
mptscsih: ioc0: >> Attempting bus reset! (sc=e9611b00)

it usually happens once there is heavy disk IO (copying of large files) - machines completely locks for a minute or so and keeps on working after that.

I also just found in the log files:

Feb 24 05:38:53 db1 kernel: SCSI host 0 channel 0 reset (pid 353977) timed out - trying harder
Feb 24 05:38:53 db1 kernel: SCSI bus is being reset for host 0 channel 0.
Feb 24 05:38:54 db1 kernel: mptscsih: OldReset scheduling BUS_RESET (sc=f7426200)
Feb 24 05:38:54 db1 kernel: SCSI host 0 channel 0 reset (pid 353978) timed out - trying harder
Feb 24 05:38:54 db1 kernel: SCSI bus is being reset for host 0 channel 0.
Feb 24 05:38:54 db1 kernel: mptscsih: OldReset scheduling BUS_RESET (sc=f73bec00)
Feb 24 05:38:54 db1 kernel: SCSI Error: (0:0:0) Status=02h (CHECK CONDITION)
Feb 24 05:38:54 db1 kernel: Key=6h (UNIT ATTENTION); FRU=02h
Feb 24 05:38:54 db1 kernel: ASC/ASCQ=29h/02h "SCSI BUS RESET OCCURRED"
Feb 24 05:38:54 db1 kernel: CDB: 2A 00 00 E3 D1 A1 00 01 40 00
Feb 24 05:38:54 db1 kernel:
Feb 24 07:39:38 db1 kernel: SCSI Error: (0:2:0) Status=02h (CHECK CONDITION)
Feb 24 07:39:38 db1 kernel: Key=6h (UNIT ATTENTION); FRU=02h
Feb 24 07:39:38 db1 kernel: ASC/ASCQ=29h/02h "SCSI BUS RESET OCCURRED"
Feb 24 07:39:38 db1 kernel: CDB: 28 00 00 00 10 7F 00 00 08 00

Reseat all your SCSI cables. If you see the errors again, replace the cable. I don't see any sense errors, so your drive is probably OK.