You need to recheck your file names on every page. I looked at every link and what I found is that the names are all duplicated;
www.own3dstudios.com/index/index.html (only needs to be index)
www.own3dstudios.com/Videos/Videos.html (lower case only and again just one videos)
www.own3dstudios.com/projj/projj.html (you get the idea)
www.own3dstudios.com/Members/Memebers.html (again with the caps and duplicated)
www.own3dstudios.com/Vidserv/Vidserv.html (same as above)
www.own3dstudios.com/merch/merch.html (duplicated naming)
www.own3dstudios.com/contact/contact.html (same as above)
The buttons do not have a full address to link to.
And one of the buttons is hiding some text.
Hopes this helps.