Hi Klaus,
Do you have a bugreport facility somewhere? Because I think I might have found one.
When I open a pano that has hotspots on Chrome 28.0.1500.72 in WebGL mode with krpano 1.16.4 or 1.16.5 I get frame rate drops when a hotspot is on screen. When the hotspot is offscreen the frame rate is immediately back to being very fluid. We have experienced this on multiple PC's in our company.
I have not tested earlier versions of 1.16. But I did test in Firefox and there seems to be no issue there although the overall fps is lower.
Best regards,
Laurens