I have a system that shows maps with Wp-Gpx-maps as defined here:
http://www.tiredofit.ca/stats-logs/map/2011-11-10. See my source code as I generate this on the fly.
As you can see, it loads it fine manually.
The problem exists when I try to load it in a PrettyPhoto window, where I get nothing. I'm assuming that becuase the PrettyPhoto window is still part of the page it is loading the same files (Jquery,GoogleMaps). At one point in time this used to work but then stopped.