Forcing server to load updated ptl files.

How do you force a Quixote sytem to reload updated PTL files?  Even
renaming a file to something else or even deleting the sources and the
associated pyc files and refreshing from a browser still serves old
versions??!!

Since this may be OT, how I can I tell Apache2 (with mod_scgi) not to
cache urls? There is no mod_cache module even in my local development
system.
Thanks in advance for any help.

Ernie.