I installed and set up a mobile menu where I copied all my main menu items over in a batch for Joomla 2.5. When I began to assign menu items to module for JMobile everything went fine. Under the JM manager I made sure the menu setting was to the new mobile menu as default. When I activated the Joomla Mobile plug in the 404 error appeared. I then set up subdomains as instructed and when I activated Joomla Mobile plug in again I got a blank web page.
Would like help since the Docs section seems to jump a little and documentation for 2.5 Joomla isn't complete.

Found issue with my server set up under my htaccess file. Fixed now and all works just fine.