I'm not sure where the Fonts_Disabled folder came from, but the other one is the default. Is there anything in it? If so, I'd move them to the "Fonts Disabled" folder and then delete the "Fonts_Disabled" folder.
Did you by any chance upgrade this Mac from an earlier version of Mac OS X, such as Tiger?
yup on both Tiger or Leopard -that were not updated from previous osx- those two folders exist. of course other apps are installed in both of those configurations
yup on both Tiger or Leopard -that were not updated from previous osx- those two folders exist. of course other apps are installed in both of those configurations
That's strange. I'm posting on an Early 2008 MBP that came native with Leopard and has never been reinstalled... only regular Software Updates applied... and that folder doesn't exist. The same is true for another Mac that came native with Snow Leopard. I'd still move everything from the Fonts_Disabled folder to the "Fonts Disabled" folder and then delete the empty folder. Open Font Book and make sure everything is OK before emptying the trash.
Font Book is used to manage fonts on your computer, including validating fonts (to make sure they're working properly) and disabling or removing fonts that aren't. You can use Font Book's Help feature for more information.