So, as you have seen, it seems to be specific to this machine, so maybe it is better disciussed here. For others’ benefit, I also have a problem with some imagery not displaying correctly. I’m now running JOSM version 5356. I have tested on a laptop also running LM13 and JOSM, and it works fine. The same JRE is used on both machines (openjdk-6-jre). I have tried openjdk-7-jre but the behaviour is the same.

Tried Oracle JRE from instructions here, but get a 404 not found on the repository. Any other ideas?