[mod_python] uneven speed results

Hi!

I was wondering why mod_python (3.2.8) has so uneven speed results, e.g.:

# ab -k -c1 -n15 some_python_site
...
Percentage of the requests served within a certain time (ms)
  50%    158
  66%    161
  75%    165
  80%    166
  90%   1173
  95%   1209
  98%   1209
  99%   1209
 100%   1209 (longest request)

When I compare it to a PHP it has constant response time on each request.
I know that the startup can take some more time but sometimes it takes a
longer time when I do refreshing the page in a browser so the startup
can't affect the response (I think :-).

What all does affect the mod_python runtime?

David