Hi Klaus,
while in Firefox the hotspots will be set to display:"none" and pointer-events:"none", I noticed in Chrome the display setting is not changed but also pointer-events:"none" gets set from "auto" to "none".
I believe it has something to do with either tx/ty/tz or ox/oy values. If I change theses values in a drag action, the display:"none" will be set sooner when changing the view (or later depending on final drag values).
I sent the project by mail some weeks ago, but I totally understand should the big update be more important right now.
Best regards,
Max
//edit:
There is a dirty workaround by adding a css class containing "display:block !important;" and "pointer-events: auto !important;" to these hotspots with a for loop in the onviewchange event. I limited the event so it would not fire with each redraw but I guess the performance still suffers a lot?