I have tried over and over to get my ASUS Radeon R9 290 to work on Mavericks 10.9.5. I got the card working in Yosemite, but prefer the old look of Mavericks. On a spare HDD, I decided to test out Mavericks. Everything works great, expect the card. I can't get past 1024x768 and only have 3MB...