Deleting sub-directories (folders) in ASP.NET 2.0 restarts the AppDomain

All the while I thought that the AppDomain only restarts when the
web.config, global.asax, bin folder (or it’s contents) is changed and
if there are considerable number of files have changed (15 is the magic
number as they say but can’t verify).

All the while I was wrong,
by default (that is without tweaks), deleting a folder under your
application will restart the AppDomain (implies but not limited to
clearing all sessions, cache etc).

Took me a considerable time to trace the issue I have more than guesses on what’s messing the application.

thanks to Performance Monitor (Start > Run > perfmon or
Adminstrative Tools > Performance) for the hints that there is
something messing with my sessions and cache.