Firefox opens every page five times
Whenever I click on a link to open a new page, Firefox opens it five times (in the same tab). So when I want to go back using the back and forward arrows, I have to click them five times to get back to my previous page. This is a new problem, since about 2 days...
Every time Firefox opened
== I guess since the last Firefox update
Do you have any extensions installed? Try Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.
Also, please update Flash: http://get.adobe.com/flashplayer/ The version you have is outdated and has security and stability problems.