> Does this have to do with enabling dri (direct rendering > interface? I remember that required 16 bits.
today i accidentaly came to similar problem when upgrading my Xorg and drivers of graphic card - dri didnt initialize well and X fall back from hardware dri to some sofware version of rendering. out of curiosity i tried lyx and it is unusable even for typing - every keystroke turn load to 100% for some 0.5 s or so... fortunately when dri is turned off, lyx is back to normal (while stellarium etc is still unusable.) pavel