WordPress installation at root directory and sub-directory

Hi,

I have installed one wordpress instance at http://gfmp.com.au/ and another wordpress instance at http://gfmp.com.au/mobile/

These are NOT multi-site installations and are separate installations.

When accessing mobile site page such as http://gfmp.com.au/mobile/finding-us/ it redirects to 404 page of root installation.

What should I do to fix this problem ?

Thanks in advance.