Cache seems to always be on

Tried to use some custom rules.
Set up the filter with no cache.
I want to use the custom filters to replace some strings with domain access (multi-domain-site).
But since updating drupal (to 6.13) and custom filters to 6.2-beta, the sites seems to be cached.

After clearing the main cache I can open a site in a specific domain and everything seems to be fine. But after switching to the same site on an other domain the custom string (custom filter) is still the same as on the first domain.

How can I force the disableing of caching???

If I put php-strings directly in the page, this works .

Kind regards

Kai