Hi, sorry it took me so long to answer (a full month... :-( ) !
You seem to have already done a few checks and we have somewhere to start ; let's see if we can push things further. Can you try to rebuild the gf2x source package on your box to see if it improves things? Snark on #debian-science -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org