Is this a git-bisect bug?

I'm using the current git.git to bisect a bug in Linus.git.

I got this far and then ran into trouble:
good 2.6.29-rc5-00094-gc951aa6
bad  2.6.29-rc5-00112-g3501033

A glance at git log will show that those two commits were
both from Feb 17 with only one other commit between them.

So, why does this happen?:

$git bisect start 3501033 c951aa6
Bisecting: 8 revisions left to test after this
be716615fe596ee117292dc615e95f707fb67fd1] x86, vm86: fix preemption bug

git log shows that commit is from Jan 13, way back in 2.6.29-rc3.
Can anyone reproduce/explain this?

Thanks!