Hi, good news: this bug is now fixed - install polybori-0.6.4-r1 and re-emerge sage-4.4.2.
The problem was indeed polybori as suggested by Paulo. The "fix" I have written removes polybori's shared objects to enforce static linkage which seems to fix the problem. If you want to read more on this bug, read http://trac.sagemath.org/sage_trac/ticket/8192 and http://trac.sagemath.org/sage_trac/ticket/2822 . Christopher
