Mod Rewrite and Mambo

Using SEF advance and I don't want to break it...

[BillyS]

I realize that there are posts describing how to use mod_rewrite to fix this problem. But I'm not familiar with the syntax of mod_rewrite (although I have looked at it) and I'm already using SEF Advance for Mambo - which uses mod_rewrite. So I see this as a specific question, hopefully someone has already encountered and solved it:

I think that Google is penalizing me in terms of PR because my home page appears this way:

www.redwidgets.com/ - PR3
www.redwidgets.com/index.php - PR2
redwidgets.com/ - PR2
www.redwidgets.com/Category/ - PR4

Is there a way to get the home page listings to all point to the same thing - www.redwidgets.com/? I've tried using redirects, but that breaks the entire site.

Thanks in advance.

[goodroi]

I'm not an expert with mod rewrite. I can tell you that Google does see widget.com different from www.widget.com.