[PHPTAL] Two sites with two identically named templates on one server?

[.: smilelover :.]

Hi,
I built 2 websites using my web engine that uses PHPTAL. Both sites have a template called "index.zpt" and are served by one Apache, from two different VirtualHosts. The problem is, that PHPTAL assumes both index.zpt files to be one file and data in the template cache (in /tmp) get mixed. I have content of one site in a template from the other site. Is it possible to solve this by something else than renaming one of the templates?

Thanks,
Dan