raidframe oddity

[der Mouse <mouse%Rodents-Montreal.ORG@localhost>]

I have a 9-disk RAIDframe RAID5 of a little over 7.25TB, on i386 4.0.
Back on Tuesday the 2nd, I set it up and started the parity
initialization.  It just finished.

The interesting thing is, it finished at 87% done, with over 11 hours
supposedly yet to go:

[Backup - root] 128> raidctl -S raid0
Reconstruction is 100% complete.
Parity Re-write is 0% complete.
Copyback is 100% complete.
Parity Re-write status:
 87% |**********************************     | ETA: 11:18:48 \
[Backup - root] 129> raidctl -S raid0
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
[Backup - root] 130> 

Any ideas why such a severe mismatch between estimate and reality, and
whether it indicates anything that could actually cause trouble?

/~\ The ASCII                             Mouse
\ / Ribbon Campaign
 X  Against HTML                mouse%rodents-montreal.org@localhost
/ \ Email!           7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B