Problem with book opening animation

Hi,
I'm trying to make book opening animation. It looks… good enough in Blender, but inside browser pages are intersecting each other during movement. I've tried "Optimize keyframes" (on/off), "Use Native Baker" (on/off).
Nothing seems to work. Problem looks a little bit like there is not enough precision with bones rotation? I don't know. Maybe one of you guys can figure it out.

Here's blend file: link
Here's html: link
Blue box starts animation

As you can see there's a lot of bones - book has to be fairly smooth. Maybe there's another way to this?

Couple thoughts:
There is a maximum allowed bone count. You have a lot there, not sure if it sure over 201.

Saw this error in the console:

print.js:119 B4W EXPORT ERROR: The "Cube" object's "Armature" armature modifier has no armature object. Modifier removed. 

Your pages are very close together. As you zoom away, a small space becomes essentially no space. So even if you get it looking good close up, zooming out can cause near by planes to fight for the same space.

You could try the Hide Object Node so the pages behind get hidden when they are not supposed to be seen.

Theoretically, you could get away with only one moving page and use the Inherit Material Node to swap out the visible texture at the right moment.

I really like your glossy pages and smooth animations. Looks like a real book.