dordale: Finally got around to looking at this again but yep, that was the problem! I never completed the [final] step of changing fonts in the eBook program as well. Strange how the issue just recently crept up since I changed the Reader fonts quite some time ago, but I'll consider it fixed. Thank you!
dpierron & grooks: I always read in portrait...haven't seen much use to reading in landscape yet. Oh, and my Reader is very secure in it's "orientation."
Thanks for the help gentlemen!