diagnosing firewire hard drive problems

[Matt Price <matt.price@utoronto.ca>]

hey folks,

I have an external firewire hard drive mounted via the scsi/firewire
system -- I store my mp3's there mainly.  

my 3-year-old turned off the drive unit's power switch one day when I
wasn't paying attention (hopefully learned a parenting lesson
there!).  Now the drive is still detected by rescan-scsci-bus.sh, and
the relevant partition will mount, but any operation I try gives the
following error:

               
[18:36:16]root@matts-mac:~$ mount /mnt/firewire2
[18:36:19]root@matts-mac:~$ ls /mnt/firewire2
ls: reading directory /mnt/firewire2: Input/output error

so my question:  how do I start figuring out what's wrong?  I'd rather
not have to delete the whole iflesystem...  

any suggestions?  
thx,

matt