oh good catch! Yeah, fauxton is quite a bit out of date. I probably did some wrong math when trying to account for offsetting the VB planes or something. My suggestion would be to check into the fauxton internal functions. I need to sit down soon and refactor fauxton since when I wrote it originally I was quite trash at coding. Haha.
Found it! I changed one specific _zs value within " __FauxtonWriteStaticSpriteStack" to 1 (bolded and commented below):
// Create and write to buffer (much faster than writing a direct vertex buffer)
for ( var i=0; i<_num * _zs; i+=1/_zs )
{
var _ind = ceil(i / _zs);
//if ( _ind > _num-1.6 ){ _ind = ceil(_ind); }
_ind = clamp(_ind, 0, _num-1);
__FauxtonWriteQuad(_buffer, sprite, _ind, _x, _y, _z + i + _zoffset, _col, _alp, _ang, _xs, _ys, 1) //changed _zs to 1 here.
}
Hope this helps anyone facing a similar issue!