So after some digging, I think the font selector under display pulls the fonts you choose from the app (or apps) in system/app folder and replaces the Droid sans fonts in system/font.
What I did was used the font switcher app in the market to try some out, but didn't use the backup system font option first. So my device was set to the jungle gothic and I used the market app to change it.
Now when I choose jungle gothic, it switches to the font I selected with the market app. I can change to other fonts listed under the font options under display.
I tried to restore a backup prior to installing the market app and overwriting, set the font to jungle gothic, copied the fonts from system/font that the market app replaces to SD card, restored newer back up with borked font, replaced overwritten system fonts with ones I pulled from back up.
After that, a reboot put me in a bootloop.
So choices were, restore old backup and live without a week of info, update apps, tweaks, etc, poor live with newer back up and no jungle gothic.
Only thing I like about jungle gothic is its a slightly larger font than the others.
Short version, don't try to change crap in system/font.
Sent from my LG-P930 using XDA App