i have htis weird problem sometimes if I press the home page button or the previous page button on my Navigation toolbar a save as dialog button pops up, if I click yes or ok it saves the page in question. Once I had disabled my antivirus temporarily and when I enabled it, firefox started working properly again. But generally the only way around it is to exit the application and start it again.

uninstall firefox then reinstall it i think it should work

Dr.thermal

make sure your AV is not running when installed
you may have to change startup for AV then reboot
check make sure Av service not running
then re-install firefox
if Av app is also firewall allow firefox exe in rules

Ill give it a go, the problem happens infrequently I dont think its antivirus realted. I just recently installed Kaspersky, I previosly had AVG I guess ill find out now

thanks