I haven't had that happen, but I did have a problem with a laptop where fonts would degrade and I think it was because of bad RAM. I recommend a RAM test. Maybe some of the memory that is rarely used -- only when you really need it -- is bad and causing the problem. This seems like a good test: http://lifehacker.com/5531900/use-an-ubuntu-live-cd-to-test-your-pcs-memory Mike On Sat, 16 Jun 2012, gregrwm wrote: > does this happen to anyone else? my main box has 1g ram, it seems > generally adequate, tho thrashwaits of several seconds can happen with > heavy use. after just such times my desktop background may sometimes > seem suddenly to have numerous adjacent rectangles swapped, sometimes a > whole array of same, quite funky to look at. then sometimes > also/instead the fonts rendering firefox and/or libreoffice may be > partly replaced with funky hieroglyphics. sometimes relaunching the app > is sufficient, sometimes i need to relaunch X. this has happened 2-3 > times/month for quite awhile, hasn't gotten worse or better, i always > keep natty uptodate, i remember the same happening with maverick, > perhaps even earlier. could be hardware, could be software, tho if > software you'd think we'd be hearing about it..? surprisingly i've not > seen a single instance of data corruption tho.