MySqlI problem

I installed and configured PunBB on my host server, but when I try to access it, the following error occurs:

This PHP environment doesn't have Improved MySQL (mysqli) support built in. Improved MySQL support is required if you want to use a MySQL 4.1 (or later) database to run this forum. Consult the PHP documentation for further assistance.

The host indeed doesn't have support for MySqlI, yet the MySql version installed is 4.1. What should I do except asking the host company to install the improved extension?

Maybe there is a way to tell PubBB, to use only the capabalities of the older MySql versions?

Thanks.