@Biim:
Do you use custom history settings in Firefox - particularly regarding cookies?
Try this - in Firefox go to Options > Privacy and check if you have "use custom settings for history" selected under History. If so, make sure you have "Accept cookies from sites" ticked and "Accept third-party cookies" set to Always.
Otherwise, you can simply select "Remember history" from the History drop down. That's how I have it and it works.
Hope that helps!