Timeout Detected on cmd[0x28] - What does it mean?

All,

I have a PE 2650 with Perc3D.   Off late we have seen situations when the 
applications go in to sleep for 10-20 seconds and it always corresponds 
with the
following entry in syslog.

Please note the application sleep preceeds  the time when error gets 
logged  (To illustrate, if the application sleeps from 10:43:10  to 
10:43:28, the aacraid error
is written at 10:43:28).


Sep 10 10:43:28 nsrp02 kernel: aacraid:ID(0:01:0) Timeout detected on 
cmd[0x28]
Sep 10 10:43:28 nsrp02 kernel: aacraid:SCSI Channel[0]: Timeout Detected 
On 1 Command(s)
Sep 10 10:43:28 nsrp02 kernel: aacraid:ID(0:01:0); Aborted Command 
[command:0x28]

What does this error mean?  Is this a hardware problem



I have added the output from afacli, in case it helps.

File raid.current.config receiving all output.

AFA0> 
COMMAND: container list 
Executing: container list 
Num          Total  Oth Chunk          Scsi   Partition 
Label Type   Size   Ctr Size   Usage   B:ID:L Offset:Size 
----- ------ ------ --- ------ ------- ------ -------------
 0    Mirror 68.3GB            Open    0:00:0 64.0KB:68.3GB 
 /dev/sda                              0:01:0 64.0KB:68.3GB 


AFA0> 
COMMAND: disk list 
Executing: disk list 

B:ID:L  Device Type     Blocks    Bytes/Block Usage            Shared Rate
------  --------------  --------- ----------- ---------------- ------ ----
0:00:0   Disk            143374650 512         Initialized      NO     160 

0:01:0   Disk            143374650 512         Initialized      NO     160 


AFA0> 
COMMAND: logfile end 
Executing: logfile end 


Any help is greatly appreciated.   If you need more info I will be glad to 
give it.