Goto http://gmap-pedometer.com/. Switch to Hybrid and zoom in as far as you can and still have the roads overlaid on the images. Click Start recording. Double click on a road somewhere. Double click somewhere else on a road. Keep drawing a path so that the map has to scroll. Watch the red start/end markers. They flash in and out instead of staying solid. Regression range: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=beab39d49de9&tochange=b26489e73818 Guessing bug 572520

You don't even need to wait for autoscroll - just scrolling around manually with the mouse causes the markers to flash. To be clear, the reason this is blocking is because it's a regression from a bug that should have had no functional change, and it seems pretty unlikely that it would be restricted to this site.

When you scroll, it seems (it is *very* hard to tell for sure, because of the crazily-obfuscated source code) that gmaps loads a new image with the same URL. In the past, we'd display that image immediately, because it was already loaded, but since bug 572520, we delay the load (= "you can display this image") events until a run through the event loop. In other words, this is a bug in the webpage. -> Tech Evang.

No issue.