I did an 'apt-get upgrade' to my testing system yesterday and got > 50 MB of upgraded packages(!)
This upgrade included version 4.10 of X. I notice now that on a large number of applications, such as the Gnome desktop and applications which have pop-up or drop-down menus, that the text has been replaced by squares (in fact, this makes Gnome essentially unusable; switching to kde restored much of the functionality). I assume this means that a particular font got messed up by the upgrade, but I really don't know where to look. Has anyone else seen this (and found a solution)? Bob