Magento ignores extra URL parameters set

Question

I am trying to open a Magento store link from an external site. While opening the store link I need to send some information using the query string parameters. So I open a link (through php code) such as: http://magentostore.com/myproduct.html?id=3434&user=445

However the Magento store link ignores the query string parameters and reloads the page as: magentostore.com/myproduct.html

I checked in Firebug and can see that there was a redirect to the Magento store without the query string parameters. Is there a way to override this behavior and let Magento load with the query string parameters? What setting can I do in the Magento store to let it allow using the query string parameters? Is there any other way of sending some more information to the Magento store page?

Is there a way to find out if its Magento doing this and not the server?

Thanks