>>How about this (see attached)? It persisted beyond the refresh.
>Right click refresh on the top right toolbar to have it fixed at the toolbar level.
>Right click refresh in the other area to have it fixed in there as well.
>For me, it is a mystery as to know why that browser is still using images from the cache even after close to a week after.

And not just that, but through several hard reboots (laptop, shut down for a day, two days, then cold-booted, etc.).

I could not get it to release the cache by doing reloads. I had to go into the preferences and manually tell the browser to clear its cache. Linux Mint 14, Firefox 20.0.