Shane, most of Adobe's documentation seems to be written with the assumption that it'll be used by C and Java programmers. But I did find the value "com.adobe.acrobat.plain-text", after some googling around, so I should think you're on the right track.

Any chance the problem is simply that the value is case-sensitive? You have the "acrobat" part of it capitalized.

(I agree putting the three parts together should be easy....once you have each part working.)