Well you'll recall that in the Performance Quiz #9 solution there was a surprising result where Test7 was actually faster than Test5 even though they appear to be doing basically exactly the same work. So my new challenge to you was to see if you can explain it.
So, now this is your last chance to go and look for yourself before I give away the answer... so stop here if you want to work on the problem.
OK if you're still reading then you're just dying to hear what was going on. Well there's a lot of serendipity here. My colleague Vance had just written a blog about how to disassemble dispatch stubs. In what I can only categorize as a total unmitigated fluke (because believe it or not we didn't discuss this with each other at all) his blog which I linked to in the original has the answer right there on a silver platter.
As Ivan Stoev wrote in the solution comments: