Some of the older catalysts, 9.2 or later IIRC had a screen corruption problem, but it was fixed in 9.4? 9.5?
Since 9.5? or 9.6? I've now gotten a new type of corruption where random rectangles (primarily on applications) will have black backgrounds which forcing a screen refresh "fixes". Dunno if that's a GNOME/GTK/X.org problem, a catalyst problem, or a combo of the two. (Other users have reported this as well, so it's not hw.)
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)