Cache problem with 4.3.1

Hello list, I upgraded my Apache to 2.0.45 and PHP to 4.3.1. Now I have 2 problems: (1) If I change something in any page on my web site (inside <? include ?>-ed file), some users can't see it until they erase cache in their browsers. I guess that's because file status change wasn't passed correctly via <? ?> tags to Apache server. (2) Besides, cache problem causes serious problems with autentification. Some people can't log in, and sometimes they are asked for autentification when it's not expected. My simple configure options: /configure --prefix=<...>/php-4.3.1 \ --with-mysql \ --with-apxs2=<path to apache2>/bin/apxs \ --enable-versioning Thanks in advance. Nikola