Oops, very minor mistake in v1.8, so download v1.8a instead. Sorry about that.
New to version 1.8a:
-Fixed a minor mistake with auto split 2-page portrait scans.
I was splitting pages at the left edge of the detected page spacing instead of the center. This should make the x coordinate of page splits a few pixels better.
(I know, not a big deal... any split within the detected page spacing should be fine, but I'm a perfectionist :P)
Enjoy and let me know if it works for you