Very strange caching problem with python script run from apache

[tinnews at isbd.co.uk]

I'm running a python script via the apache ExtFilterDefine directive,
it works basically as expected *except* that when I change the script
apache/firefox continue to run the old version of the python script
until I remove the script completely and then replace it.

I.e. my script is called tl2html.py, if I change it to (say) add
several lines of output the added lines don't appear on firefox.
I can restart firefox and I can restart apache and *still* it runs the
old version of tl2html.py.  If I 'mv tl2html.py fred' and then
redisplay the page I get an error (because the script isn't there) and
if I then 'mv fred tl2html.py' the new version of the script is run
and I get my expected extra lines.

This makes dubugging/development *exceedingly* difficult!

Where is this python being cached?

-- 
Chris Green