Nope, the logic is in the control, a button click should page up/down. I'll add some logging messages to see if we can't locate why it is not working... Look for another DLL later today.
Unfortunately, I am off on another business trip starting tomorrow (Thur) for 1 week. If I get this log today, and I have time to locate problem and fix, I will do so, otherwise, this'll be on the shelf for a week til I get back...
Hmm... Looks like the MoreUp and MoreDown rectangles are the same x=76, y=82.5, width=2, height=4.5. Not sure if that was a mistake in my log message, or something in your skin.xml. Regardless, the click 79.13, 84.39 falls outside of that rectangle, so it will not trigger the up/dn logic.
Unfortunately I am away from my dev machine for a week, so will not be able to troubleshoot this. Can you send me your skin.xml, and when I get back I'll try to re-create on my machine.