Mason forgets to use local

I thought I’d find this problem in the archives/FAQs, but I can’t…

Some mods I had made to Mason pages mysteriously disappeared
recently from the Web UI, and a new page I had added started to return a
404 error.
The apache log said:
[error] [Mason] File does not exist:

Well of course that file doesn’t exist, it’s in the rt/local hierarchy as
are my mods
to existing pages.

I stopped & started apache and, magically, my mods and my new page

So my question is, why would Mason suddenly forget to look in the local
area, and why would an apache stop/start jog its memory?

RT 3.0.8, mod_perl 1.29, Mason 1.23