#115 log does not display all branch info

[Dave Polaschek]

In some cases at least, doing a Status->Get Log will show branch
information below the line, but not above. That is, I can see
revisions 1.87.2.1-4 in the bottom half of the window, but in the
top-half, only 1.87 is visible (and therefore selectable for "Checkout
As...")

I don't have a good recipe for replicating this, but once you've
reached this state with a file, it seems it will never work again.