[Freesurfer] tksurfer display problem

Hi, when trying to look at surfaces in tksurfer, all I see is a small part of the data in the posterior of the brain (see attached for example). There are no errors on the command line when I run tksurfer. This only started happening very recently. Here's some system info: (CentOS 5.5, 64-bit; FreeSurfer v5.0)

[freesurfer@occipital TGA]$ uname -a Linux occipital.tch.harvard.edu 2.6.18-194.26.1.el5 #1 SMP Tue Nov 9 12:54:20 EST 2010 x86_64 x86_64 x86_64 GNU/Linux

[freesurfer@occipital TGA]$ /sbin/lspci | grep -i nv 40:00.0 VGA compatible controller: nVidia Corporation G73GL [Quadro FX 560] (rev a1)

I wouldn't think I need to update my graphics card driver. But, does anyone know how to fix this?

Thanks, Chris