blarg - I am fairly sure you are right HugeLunatic (ot: thanks for the input on my blog! I am retarded when sleep deprived and it's 05h30)
tinkerbell, The Aspyr site has only a vague statement:
ATI Radeon 9800 or better for The Sims 2 (no EPs)
but then specifies
ATI Radeon 9600, 9700, 9800, X600, X800, X1600, X1900 for The Sims 2 Seasons Expansion Pack - which seems to be crazy since the 9600 is NOT better than the 9800.
They don't list any of the ATI 2000 series of chips, so I am not certain when they will add support for this new (and superior to anything they have listed) video chipset. In fact, I don't think the PC versions of the game would support this card any better; neither EA nor Aspyr seem to have done much to make the game compatible with the newest video cards
You might try trying different settings if your extenions offer a custom setting, but go carefully there, MacOSX being based on BSDos will probably let you specify a setting that will fry your video card and monitor in a hurry. I know this for a fact, since I have done it by mistake on more than one occasion setting up fBSD and BSDos.
