I use website boxes to show text that explains details in the pano.
The code PTP generates expects the html to be in the root of the tour. In the code it says "/file.html" but in fact the viewer is looking for the file in "../file.html". (This is a known issue since long, but noone seems to care).
Most likely because people use absolute URLs anyway. When I use absolute URLs the system works fine. The BIG problem is, that the tour will be distributed as a package to many people. The need to tell everyone to change 40 paths to the url where the tour is hosted on their webserver is unbearable and complete nonsense.
When I use a path like %FIRSTXML%../file.html the html is displayed on my computer but not on the customer's computer although all caches are cleared and we both are looking at the same sources over the web.