Rails - May 2006 - Intermittent failure to automatically include all models

I have two models in my rails app that inherit from ValidatingBase
instead of ActiveRecord.  I didn''t start having this issue until I
switched to Planet Argon, running lighttpd, but I''ve started to get
errors where one or the other models doesn''t get included and I get an
"uninitialized constant ModelName" error.  The weirdest thing is that
when I restart lighty it sometimes includes one of the models and
sometimes the other model, so my errors seem to vary.  Has anyone seen
this before?  Is there a way I can make my app load certain models
explicity to avoid this bug?

Thanks,
Carl