problem solved. Thanks for making me think about the driver! I don't know quite what I did, but I went through a cycle of uninstalling and reinstalling the graphics driver, attempting and failing to use the system>administration>hardware drivers tool to set the 'proprietary driver', reconfiguring X, and tinkering with the ATI Catalyst tool. Anyway it all works now hurray! Also I found that setting the display preferences to use 'visual effects' (which I normally avoid) makes Croquet run very fast.


Cheers!