Google page rank problem

How can I improve my ranking

[cocacolafun]

How would you go around this:
http://example.com/index.cgi?from= has a higher rank than http://example.com/index.cgi

I allow my users to refer their friends and each users has a different url:
http://example.com/index.cgi?from=url1
http://example.coml/index.cgi?from=url2
http://example.com/index.cgi?from=url3

But google PR give different rank for each one of these URLs. But the reality is that each one of these page return the same thing than if they were accessing http://example.com/index.cgi

CCF

[edited by: tedster at 3:05 pm (utc) on Sep. 6, 2007]
[edit reason] use example.com [/edit]

[tedster]

As you've discovered these are each different urls, and yes, having them all indexed can undermine your rankings. How to fix this kind of issue depends on your specific situation. It sounds like these "extra" query string urls do have backlinks - if so, I would suggest a 301 redirect from each of those urls to the main url. If not, you might also just deny them in robots.txt.