I listed my system specs (page 7). Probably similiar to Yours.
I found it was neccessary to turn off the texture compression. Before I did that, I was having graphical glitches and crashes on various important functions, like trading. Turning compression off fixed that.
Now, the game regularly crashes when I quit. It hangs for about 20 seconds, then the crash window pops up.
Also, the game becomes very slow when I enter some regions. But after a few seconds, it is faster again. I guess that is because of texture caching. Really not an issue for me, because the effect is only temporary. After a short waiting time, the game runs as fast as before.
*edit*
Since I cannot reply to private messages yet, thanks for Your message Shadallark! I believe i found the problem at the same time that You wrote the message to me. That's really fast help!
Besides, the Mac guide and the comments on them confused me a little: It states that I shall run the updater. But the updater currently does not work. In one thread, it says that the updater problem will be fixed soon. In another thread, it says that the updater shall not be run on the Mac at all. Maybe You could clarify this as a note in the guide?
*edit*
A note on the crashes on application quitting: It seems that my configuration in fact WAS saved. But the crashes definitely happen every time I quit.
[ Please avoid making one post right after the other in the same thread. Just "Modify" your first post to add more information. Thanks! --Karyuu ]