Abandoned cart problem


I am using piwik and tried to install piwik ecommerce tracking. I have a problem with the abandoned cart as I suspect that each unique user in our website that differs in ip every time they visit.
Each visit of unique user per day records his abandoned cart then the next day as he visits again it records as different abandoned cart as another different user. Thats why our revenue left in cart goes higher and higher which is not reliable/true to what really is in our abandoned cart. How can i fix this each user can only record as one abandoned cart?

I think I might have a problem same as this forum: 301 Moved Permanently

but the link you gave the last http://dev.piwik.org/trac/changeset/5171 as a solution is broken it says: No changeset 5171 in the repository