I believe that option is enabled by default, but I "emerged" it, so Gentoo handles it (I have cups as one of my USE flags, so it should). Cups has been restarted. The printer status shows up, the printer prints, it just is printing garbage, in the same place on the same page over and over again. It doesn't show up as "officially supported" on the gimp-print web page for gutenprint 5.0.0 rc3, it only goes up to Stylus C84, but linuxprinting.org says it works "mostly", so I guess someone has had to get it to work...
Edit: Also, it's probably useful to know I do have a working printer w/ cups, I have an HP PSC-750 working right now and plugged into the computer as well, albeit w/ next to no ink