Annoying error please help!

[eluser]Unknown[/eluser]
Hi All!
My site was developed using CodeIgniter, and i never ran into this weird issue until a new sever switch. Basically if you click any link on my site it displays but loads up the mainpage again. If you add two slashes in the URL, the page loads (ex. http://boxaproject.com/project/details/10 - does not work http://boxaproject.com//project/details/10 - works.

Any ideas? I know its a server side issue, I just cannot find out what to enable/disable in php.ini or httpd.conf to make this go away..

Thanks for any help!