I can confirm that the flipping problem is a hardware issue, as using the original ipdf binary from iRex still exhibit this problem. My flipbar actually got worse, now it won't even respond to forward flips sometimes!
So I've updated my patch to help people who have similar problems with their flipbars:
1. both long and short flips only flip a single page now;
2. up and down arrows are now mapped to long flips.
Further more, I've also updated the continuous mode to display and center only new contents from the same page. It's only for vertical viewing, and the margin problem is also adjusted. Hopefully it'll work better now. You can give it a try.
I'm only attaching the new binary here as I've mistakenly overwritten the source code by an old copy and consequently lost the new modifications
PS: To compile from source on your own linux PC you need to setup the toolchain for cross-compilation. I won't go into the details as there are already documentations that can be found on iRex site as well as this forum.