zfs discuss - Dec 2007 - scrub percentage complete decreasing, but without snaps.

I''ve seen the problems with bug 6343667, but I haven''t seen
the problem
I have at the the moment.

I started a scrub of a b72 system that doesn''t have any recent
snapshots
(none since the last scrub) and the % complete is cycling:

 scrub: scrub in progress, 69.08% done, 0h13m to go
 scrub: scrub in progress, 46.63% done, 0h28m to go
 scrub: scrub in progress, 6.36% done, 1h37m to go
 scrub: scrub in progress, 2.09% done, 1h11m to go
 scrub: scrub in progress, 0.02% done, 33h17m to go
 scrub: scrub in progress, 0.00% done, 44h39m to go
 scrub: scrub in progress, 0.00% done, 43h17m to go
 scrub: scrub in progress, 0.00% done, 35h6m to go
 scrub: scrub in progress, 1.97% done, 1h6m to go
 scrub: scrub in progress, 4.16% done, 1h21m to go
 scrub: scrub in progress, 3.91% done, 1h15m to go
 scrub: scrub in progress, 1.62% done, 1h10m to go
 scrub: scrub in progress, 0.41% done, 2h6m to go
 scrub: scrub in progress, 0.02% done, 31h18m to go
config:

        NAME        STATE     READ WRITE CKSUM
        export      ONLINE       0     0     0
          mirror    ONLINE       0     0     0
            c3d0    ONLINE       0     0     0
            c1d0    ONLINE       0     0     0
          mirror    ONLINE       0     0     0
            c4d0    ONLINE       0     0     0
            c6d0    ONLINE       0     0     0
          mirror    ONLINE       0     0     0
            c7d0    ONLINE       0     0     0
            c8d0    ONLINE       0     0     0
          mirror    ONLINE       0     0     0
            c9d0    ONLINE       0     0     0
            c10d0   ONLINE       0     0     0

errors: No known data errors