Another data point: I was running my X server in 16-bit graphics mode. If I switched to 24-bit, the Firefox loads correctly with the Human theme. My x86 laptop has no problems in either 16-bit or 24-bit depths.
So the requirements to reproduce seem to be:
* x86-64
* 16-bit depth
* Human control theme (== ubuntulooks theme engine)
Another data point: I was running my X server in 16-bit graphics mode. If I switched to 24-bit, the Firefox loads correctly with the Human theme. My x86 laptop has no problems in either 16-bit or 24-bit depths.
So the requirements to reproduce seem to be:
* x86-64
* 16-bit depth
* Human control theme (== ubuntulooks theme engine)
Does that match anyone else's observations?