User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:38.0) Gecko/20100101 Firefox/38.0 Build ID: 20150131151030 Steps to reproduce: I have an issue that is very difficult to reproduce. You may need a mouse with a back button. Go here http://curl.haxx.se/logo/ Click any file there, (I could reproduce with all including the README) then click the back mouse button to go back. You may have to do this up to several hundred times. Actual results: Occasionally it will not go back. Or, rather, it goes back but the content doesn't update. Maybe one of every few dozen tries the former page remains even though Nightly seems to think it actually went back. This is hard to explain so I made a short video of it happening. What you see in the video is me clicking on an image link, then once the image appears clicking back. The video shows the repro in seconds but actually it took many many tries to get that done in a few seconds. I was able to reproduce regardless of hardware acceleration settings, and in a clean profile with no extensions or addons enabled. I was not able to reproduce without e10s, however I did not have the time to devote to it so I'm not prepared to say this is e10s related. Expected results: The back button should always do exactly that.

I can be pretty sure that it's bug #1067470, can you confirm this?

It (In reply to Virtual_ManPL [:Virtual] from comment #1) > I can be pretty sure that it's bug #1067470, can you confirm this? It looks like it but switching applications did nothing to force a repaint. I could select the hidden links on the page to make them appear so the page is definitely there just hidden (see attachment). When I opened a new tab (CTRL+T) and then closed it the page was no longer hidden so I guess that causes a repaint. BTW it was almost impossible to reproduce this time, I don't know why. It took me like 15 minutes.

Looking on your screenshot and that the content appear on mouse movement, it's definitely a bug #1067470. Thank you very much for reply.