Sounds like this was just incidental, since the MC locked fine also with the tickler enabled for weeks.
The tickle is disabled by the down script, but there's no way to correctly handle all possible button pushes. If you want to disable the autolocker for some reason you should run mcdown before trying to lock. This will set up things with the correct settings.
Isn't that backwards? Shouldn't the tickler be enabled by the down script, and disabled by the up script? Either way, the problem was that, after I acquired lock, the tickler was causing the transmitted power to fluctuate by ~20%, and often the MC would lose lock after a minute or so. Also, the WFS definitely couldn't be enabled by hand.
Anyhow, I'll try to keep in mind that this exists, so I'm not stymied by it again.