Error 16: Inconsistent filesystem structure

[Lorenzo Nizzi Grifi]

Well this is my configuration:

Main board:
Asus P4B

Two EIDE hard disk ( Quantum and Maxtor ):

- hda : Windows ( Primary master )
- hdc : Linux (  Secondary Master )  with  the swap partition on hdc1 and 
root filesystem on hdc2 .  I have  a Slack 8

I downloaded, compiled and installed Grub 0-91 as the manual suggests ( I 
copied all the needed files in /boot/grub ) and i created a menu.lst file 
that I've placed in /boot/grub as well:

default 0
timeout 30

title Slack
kernel (hd1,1)/boot/vmlinuz-2.4.17 root=/dev/hdc2 append="hdb=ide-scsi 
hdd=ide-scsi"

title Windows
root (hd0,0)
makeactive
chainloader +1

After I ran grub and typed:
root (hd1,1)
setup (hd0)

No errors came out so I thought that everything was right but when I tried 
to reboot my pc Grub says to wait that he was loading stage1_5 and  after 
one second he came out with the infamous Error 16.
I tried to make a floppy with grub on ( I followed the instructions 
reported in the FAQ ) and the only difference is that this time I can choose
the system to boot ( so no problem with the menu interface ) but If I 
choose linux I have the error number 16 :

Error 16: Inconsistent filesystem structure

Windows can boot correctly instead...no problems...:-\

What can I do? Thanks a lot!
Lorenzo