I have an application on a Intranet in PHP that works fine and i can see everything. When i try to access that from outside the intranet, one page may show up now and on the next request for this page it won't (in some machines never show the page). I have the main page that always appears but when i try to access the others from that page, sometimes i see the page and sometimes i receive a message saying that the page can't be display.

I have others applications with ASP in the same machine and i don't have this problem. 

Thanks,
Andrea