Using your good plugins I found that IFRAME calculated size is wrong.
The IFRAME width must be less than container width.
The width must be (container width) – (padding*2+border*2).
Also IFRAME height must be decreased of (padding*2+border*2)
Using a panobox where include HTML file is rendered full screen (tested with Pano2VR and PtGui html file), the right side of IFRAME is over the right side of panobox.