[CentOS] Odd fsck problem

In the last month - definitely after going to 5.5 - I've tried to fsck a
drive (340 days, or some such, unchecked). 960G RAID 5, I *think*,
possibly serial port attachment to a JetStore RAID array. Every time I
try, it gets to 70.0%, and stops. As in, I left it run last night, having
started it late afternoon, and around 23:00, it was still exactly there,
not even .1% more. On that, I also had a -dd flag, since running it the
other day with a -d gave me nothing at all of debugging info; neither did
the dd.

Note that my manager tried to run one on another server, also attached to
a JetStore, and it also stopped at the exact same point. This has never
happened before, and fsck has handled these in the past.

Anyone seen anything like this, and/or have ideas as to what I can do to
fsck to at least *tell* me why it was gagging?

         mark