chkdsk "unspecified error" on verifying indexes (stage 2 of 3)

Hi,
I've been getting "corrupted data" popups in xp, which show
you the "corrupted" files and suggest running chkdsk. I've
run chkdsk, this is the screenshot:
http://www.missouri.edu/~jsd8cc/img/chkdsk.gif

But I get an "unspecified error" around 80% of the
verifying indexes (stage 2 of 3), and chkdsk stops.

This is NOT my boot drive (with windows), it is just a
storage disk, mainly with mp3s.

I've also run Norton Disk Doctor, and it reports:
"FILE STRUCTURE STATUS:
Deleting orphan file record segment 32188.
Deleting orphan file..."
etc.

and it also says,

"INDEXES STATUS:
An unspecified error occured."

Obviously there is something wrong with the indexes, but
chkdsk can't fix it, so what can I do? Is there a tool out
there that can help me?

Thanks