[O] debugging Agenda keyword view?

[Eric Abrahamsen]

I've never had much luck getting the keyword Agenda view to work
correctly: there was a mention here before about Agenda file/buffer
restrictions piling up over time, not getting cleared, but I don't
actually use such restrictions much, and I still have the problem.

It seems like the longer I've had Emacs/Org up and running, the less the
keyword Agenda search can find. The regexp search always works
correctly, but the keyword search just finds progressively fewer and
fewer entries. I haven't yet been able to see a pattern, but restarting
Emacs fixes it -- I can find everything again.

Has anyone seen this before? I'll go code diving in a few days, but if
anyone has any insights in the meantime, please let me know...

Eric