php.ini

Hi, I've set up and tested php 4.5 on IIS4 on an NT machine. This machine supports several hosted domain web sites and each has it's own IP. My problem is that I specified the Document Root in php.ini, having it pointed at the root of the first web on which I wanted php installed. That worked fine until I went to enable it on the second hosted web site, which then showed the Document Root of the first. Clearing the document_root entry in php.ini (leaving it empty) and re-starting all IIS webs had no effect. The second web still reports the document_root of the first. Can someone please help me to get each hosted web to show it's own root directory ? Thanks, Kevin.