[Exim] Problem with system_filter

Hi,

I have a problem with the latest sytem_filter.exim (v 0.17).
The filter has no problem blocking .exe files, but does not
want to block any of the other formats specified in the filter.
eg. .src/.com/.pif etc.

I am still using exim 3.33.

What could the problem be? I would like to avoid upgrading
to 4.x for now.

Greatly appreciated,

- Jaco van der Schyff
jvds@???