Javascript not register LAN users

Hi

Im having problems using my piwik in a web server with internal users. Before piwik was in the same server with web, but to optimize I decided to change to other internal webserver. For my sorprise when I changed the Javascript code to the new only receive external Ips, and putting html code starts to receive internal too. Any idea of the reason? There are some changes between servers (different php version (5.2 and 5.3) and I don’t know If more. How i can view the problem generated? Are any form?

Thanks