Seemingly randomly our web servers blow up and return nothing but this error,
always when trying to access the request object in session_start.  We have
made sure to always refence it as context.request, but that has not fixed the
issue.  The only way to get the servers back up is to restart IIS.  Does
anyone know what causes this problem?  Is it related to many others re:
worker process recycling?  We're dying because we are under extremely heavy
loads and this is occurring more and more frequently.