According to GNU/Grub 0.97 manual
Code:
17 : Cannot mount selected partition
This error is returned if the partition requested exists, but the filesystem type cannot be recognized by GRUB.
My guess is Grub not booting the correct partition. This could be caused by your hard boot mis-arranging the boot disk order.
To investigate you can press "c" key and drop into a Grub prompt and then issue these commands
Code:
geometry (hd0)
geometry (hd1)
If your disk order is correct then (hd0) should show up two partitions both Type 83 whereas (hd1) will have Type 82 in partition 0 because it is a swap.
Can you confirm if (hd0) is your sda?
Can you post here the output of
say using a Live CD