Thread title says it all, really. Not a major problem at all but it makes finding specific alpha/PZ/TS maps difficult.
I've only seen this once on a linux system I was setting up for testing. It was a vmware'd version of ubuntu and had some oddball system fonts (arial was missing I think) and lacked a proper GPU driver. I later went with a ubuntu 12 installation with GPU drivers for vmware and everything was fine. Those are the only hints I have...