Ordinarily, I would also point to I/O errors, but not this time. I have had this same version of Mathematica, 5.2, for *years*, on this same machine, over several kernels and several Xorg upgrades, and it was rock-solid. Not one X hang or crash. Ever. No error messages or I/O warnings ever. The only thing I'd ever see in the console would be GTK+ errors from other programs. Something about this latest X upgrade is making Mathematica unhappy, either because some previously supported format that worked fine with it has been altered or something else in that general regard. This version being so outdated - that isn't a surprise. It may not be a bug, so much as an incompatibility, perhaps
I think the only thing I can do at this point that probably will fix this is to go to stable arch, but I am not willing to do that because I like my box the way it is now :-) It's great and efficient for all other things. Before I can get a local Mathematica upgrade, I will have to resort to using it via X forwarding off the central server.
