Layout moved in Firefox

I though i had solved the problems after updating, but it seems not :p

This aparently only happens with Firefox browsers, but the content appears totally moved to the right of the menubar instead of below

http://s8.postimg.org/9rm0zoyhg/borrar.jpg

I’ve also noticed that some things i had as transparent are now opaque, and i can’t find a way to make them transparent again, specially the sidebar and menubar.

http://s23.postimg.org/w9jdcde16/borrar_2.jpg