Cookie problem

I have an AdTracker software and have this problem: When I put the code on all pages to track referrals, the script tracks all pages and not only the first one. This script tracks the link that got me the sale so I know exactly what site, webpage got me the sale and what keyword got me the new client (if the visitor came from a search engine). For example: lets say I do a search on Google for the keyword "hosting" and click on [login to view URL] the script tracks the URL [login to view URL];q=hosting&btnG=Rechercher&meta= But if I clik on another link on that site, lets say [login to view URL] the script tracks this link and when I go to the buy page the sale tracker will show the last page that I visited on [login to view URL] as the referral and not [login to view URL] with the keyword "hosting". This script worked perfectly before the php upgrade, now it tracks every page on my site but want to track on the referral URL. Thanks for bidding.