i has the same thing:
R_ProgramVariable: "GLOWSCALE" - No program bound. (src/client/renderer/r_state.c: line 566)
there is a LOT of this string in ~/.xsession-errors file (when the game is launched using KDE menu icon). Shaders a turned on.
"a LOT" - means that .xsession-errors becames 3-5-10 and more gigabytes after 10-20 minutes of playing, untill it eats all free space in /home.
i'm using latest revision from svn, 2.3 branch (r30468).
Ubuntu linux 9.10.
NVidia GeForce 7600, proprietary NVidia's drivers.