Antialiasing & text corruption - ATI 9600 Pro

I have installed a Radeon 9600 Pro 128Mb card into my machine to replace the integrated graphics, and I've been able to up some sliders to improve eye candy. However I have anggle with Antialiasing (AA).When I have AA switched on I get corruption of the text in the ATC window and on the FPS readout at the top of screen (can't remember if ATIS text is affected or not).This occurs whether I have AA set on under the ATI control panel or under FS2002's display settings.I also get it with both the ATI Catalyst 5.4 drivers and the Omega 5.2 drivers.IIRC I also saw a similar problem years ago using AA on FS98, although it was the entire panel which was being corrupted by the AA routine.Any help would be much appreciated.