I'm not entirely certain that a shorter bow is less accurate per say, but the shorter bows definately are a little tougher to steady(not like we are holding for a huge amount of time---but still have to be steady), and the finger pinch issue already mentioned above could be an issue. I have to second the Arroyo here-----very smooth, quiet, and zero stack out to a long draw.
The short bow will shoot more accurately than the nut holding the handle(to borrow a term I read today). A bow is only as accurate as the shooter. Try a shorter bow and practice, practice, practice.