[aftbit]

I've found that even in cases where a normal refresh won't restart the animations, a Ctrl-F5 will (forcing the images to be reloaded from the server, instead of cache). This is in Firefox on Arch.

[jrapdx3]

Though in this particular case, just reloading the page restarted the animations just fine. Even so, I'll try C-F5 to see if that's better.