Chris G wrote:
I've obviously changed something somewhere that has made Firefox stop using the system default font settings but I can't fathom out what/where.
By this I mean the font used for all of Firefox's menus, etc. not the font used when displaying web pages.
On closer examination it seems that if I change the desktop settings to something very different (e.g. Courier), then everything changes to that font. However when I change to my preferred DejaVu Sans then everything *except* Firefox changes to that and Firefox changes to a poor imitation of it. The font used in Firefox is not so tall and is less bold.
In addition Firefox seems unable to use DejaVu Sans for web pages too.
It's as if Firefox can't see DejaVu Sans but can see all the other fonts.
You've looked at 'Edit', 'Preferences'?