this sounds like a problem possibly caused by malicious software on your pc. please go to firefox > addons > extensions & remove any suspicious entries (toolbars, things that you have not installed intentionally, etc). also go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there and do a full scan of your system with the security software that you have in place and/or a different tool like the [http://www.malwarebytes.org/products/malwarebytes_free free version of malwarebytes]. [[Remove a toolbar that has taken over your Firefox search or home page]] [[Troubleshoot Firefox issues caused by malware]] please also [[Update Firefox to the latest version]], version 11 contains various known security vulnerabilities which were fixed in subsequent versions. by using an outdated browser you put the integrity of your system and your personal data at risk. there appear to be two versions of the adobe flash plugin installed on your system (you can check in firefox under tools > addons > plugins). try to use the adobe [http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html flash uninstaller] to remove them both and then install a fresh version from [www.adobe.com/go/getflash].

Problem solved. Thanks

what solved the problem?

I upgraded to v16 and deleted some toolbars as suggested by madperson - I should have noted it as solved - sorry