GRUB Error 17

[Cassiel <raffaele.morelli@gmail.com>]

Hello list,

as you guess I am having serious boot problems, grub loading fails at stage 1.5 with "Error 17". 

I did not install/re-install anything, resize partitions or anything else could do something wrong. I was trasferring data from my usb HD when the process stopped (input/output error) and the system went completely frozen.
>From that moment on I can not boot from HD.

Using knoppix I can read all partitions... exept /home and /

I tried to reinstall grub on MBR using the ubuntu studio rescue (apologize for that :-) ) and SGD (Super Grub Disk). 
The former stops during device mapping, showing partitions like /dev/sd1, /dev/sd2 and so on which is quite absurd, the latter is unable to install grub on the MBR (for the same problem I guess ...) and to boot any of the two OS  (XP is there, but I do not boot it from ages )

I would prefer not to do a fresh install if not necessary even if my data are backed up on a safe partition.

Any ideas? Can I resume my lenny?

regards
raffaele