PERFECT, that did the trick! Thanks for all the assistance! With those kinks worked out, GTG looks so much more useful and user-friendly than other available preprocessing toolboxes!

One more (hopefully) quick question, I was interested in using more complex non-linear warping algorithms (ANTS; http://stnava.github.io/ANTs/) to minimize any registration issues. Thinking about GTG and also pre-processing detailed by Power (and others), would it be best to:
-First slice-time correct, rigid body realign, intensity normalize, scrub, regress out nuisance variables (all in GTG), then use non-linear registration (in ANTS) and pull ROIs values out in template space (perhaps going back to GTG)
OR
-Should I simply register a subject's T1 to my template (MNI with ROIs), invert the non-linear transform, and pull ROI values in subject space (in GTG after all those steps noted above)?

Any thoughts are greatly appreciated!
Thanks again!