There's a similar bug in NWN2, but I figured that i was related to shadows(which many version ago already had a general problem even under windows + nVidia card--thought that it may have re-appeared), and the fade in/out of objects..
(This was under 9.7 + Ubuntu 9.04 x86-64, haven't played it since installing 9.8, but AMD also forgot to include part of the package, a prog/script to escalate CCC privileges in Ubuntu, solvable by pre-pending gksu to start up in menu item. Needed this right away since catalyst has memory problems wrt Desktop Resolution...)
Intel Core 2 Duo P8600, 4GB DDR2-800, 320GB 7200RPM WDC WD3200BEKT-22F3T0, ATI Mobility Radeon HD 4850 512MB GDDR3, 8x Super multi DVD+/-RW, 1680x1050 (17"), 9 cell battery
Ubuntu 8.10 x86-64 (current updates) catalyst 9.3
Windows Vista Home Premium 32b SP1 (current update) still on shipped catalyst(8.12 I think, MSI packed -- lazy)