Hi,
this is not a krpano bug, this means that Chrome has rendering performance problems when either mixing WebGL (pano) and CSS3D (hotspots) content or just when drawing CSS3D content on your system.
Check this url in Chrome to see if everything is hardware accelerated:
chrome://gpu/
If not try updating your graphic card drivers or try contacting Google about that performance problem (
Chromium Bug tracker).
Best regards,
Klaus