While browsing normally Firefox just slows to a halt and eats up a whole lot of RAM. When this happens it also won't close properly and i have to terminate the process in the task manager. And sometimes it won't terminate properly when i close all windows, so when i open it again i the the message that "Firefox is already running. If you want to open a new window you must first terminate the process".

This happens several times a day and these events are not logged as crashes.