scsi driver problems with laptop hard drive on Feisty 7.04

[Rich Lott]

Hi

I've recently upgraded my laptop hard drive (HITACHI_DK23DA-4) and it keeps 
making a strange noise. Bare with me while I try to explain that further(!)

Every so often at intervals of a few seconds or a few minutes it makes a noise 
that sounds to me like the heads are being parked (do HDs still do that?), a 
second or two of purring (like it's reading a big file) followed by a 
scratchy ca-chink noise. As it's purring the system hangs for a second (maybe 
less).

Enough of my noise descriptions, I realise they're probably not helpful!

I noticed that ubuntu uses libata for my drives so it is /dev/sda1 
not /dev/hda1. So upping the log level for scsi with

$ sudo sysctl dev.scsi.logging_level=5 

and looking in syslog, I saw the following messages repeated a million (ok, I 
didn't count them) times:

------------------8<----------------------
May 21 06:55:17 reech kernel: [ 3609.351000] Error handler scsi_eh_1 sleeping
May 21 06:55:17 reech kernel: [ 3609.352000] Error handler scsi_eh_1 waking up
May 21 06:55:17 reech kernel: [ 3609.354000] scsi_eh_1: flush finish cmd: 
df8eeb00
May 21 06:55:17 reech kernel: [ 3609.354000] scsi_restart_operations: waking 
up host to restart
May 21 06:55:17 reech kernel: [ 3609.354000] Error handler scsi_eh_1 sleeping
May 21 06:55:17 reech kernel: [ 3609.355000] Error handler scsi_eh_1 waking up
May 21 06:55:17 reech kernel: [ 3609.357000] scsi_eh_1: flush finish cmd: 
df8eeb00
May 21 06:55:17 reech kernel: [ 3609.357000] scsi_restart_operations: waking 
up host to restart
May 21 06:55:17 reech kernel: [ 3609.357000] Error handler scsi_eh_1 sleeping
------------------8<----------------------

Anyone got any ideas?

Many thanks,
Rich.