[mhennessy]

I had some of this happen this morning. I noticed that images opened in a new tab rather than in the Javascript image viewer.

Simply did a Ctrl+F5, and the problem was instantly solved. No need to delete cookies or empty the cache.

Note that this is different to pressing F5 on its own - that will simply re-request the HTML, but will re-use any other elements that are already in the cache. Holding down Ctrl while pressing F5 tells the browser to re-fetch everything the page needs.

I'm using Firefox, but I've seen this exact thing in every other mainstream browser - and in each case, Ctrl+F5 was the fix. Content held in local caches can go stale for whatever reason. In my experience, Firefox is no worse than any other browser for this - it's just that - fairly obviously - you'll likely only notice it on Firefox if that's your main browser.

You can play about with the browser settings to alter the behaviour of your cache, but these days I just leave everything on the default settings... There's dozens of browser.cache settings on the Firefox about:config screen - there's a lot of complexity beneath the surface of a modern web browser, so it's understandable that it needs a bit of a "prod" now and again.