Galaxy S2 T-Mobile SGH-T989 with root. I got fonts to work. You will need root to do it though.
Download it here http://download.rockbox.org/release/3.13/rockbox-fonts-3.13.zip
put it on your phone. Extract it to /data/data/org.rockbox/app_rockbox/rockbox/fonts - there should only be one font in there.
next you have to use the shell. either through your comp or on the phone you use a terminal
su, go into that exact directory and do "chmod 777 *" without quotes which gives full access to every font in that folder
Now they work when I select them, before I could only select them but they would never take effect.
Having some problems with bringing the player back to the screen after it's been playing in the background. Loading a song while a song from the database was already playing same problem.
bye bye Neutron Player.
You actually can just put in in the 'rockbox' directory in your sdcard. It works the same.