I have encountered a caching problem with Firefox 6. While working on one of my Joomla sites today I was updating a number of older articles and their corresponding SEF Url's. I later noticed when I clicked the article links on the web site it was taking me to the wrong page despite the SEF link being 100% correct. I first thought there was something wrong with my trusted SEF component but then later discovered the problem was with Firefox 6 caching stuff incorrectly. I confirmed this using 4 other browsers, Chrome, Safari, Opera and Internet Explorer which all see and open the correct page. The only way to clear this problem in Firefox 6 is to open the preferences, clear the cache, close firefox, reopen it. Clearly there are some caching problems with FF 6 and it's disappointing because overall this is the first release of Mozilla in nearly a year that is actually stable.