What you need:
QE not working after 10.5.8 update.
1) Go to System Profiler (About this mac > More info)
2) Click Graphics/Displays, you need:
Device ID (The bit after 0x)
Vendor (The bit after 0x)
If your Device ID is 0x9460 and your vendor id is 0x1002, install this kext it will just work for you:
I'm pretty sure this should work for most if not all 4890 1024mb cards.
Ok now, download this kext if your ids don't match the above, then follow these instructions:
Open up the kext (Show package contents)
Go to (Inside the kext): /Contents/MacOS/
Move ATIRadeonX2000 out of there, but leave the window open, extract it to your desktop or something.
Now open up 0xED:
File > Open
Find the ATIRadeonX2000 and open it.
Now hit cmd+f (Find) and do the following:
Put in the search box: C071 (That's a zero)
Take your device id, and move the last 2 chars to the front (9460 becomes 6094)
Put that in the replace box and hit replace all.
Now hit cmd+f (Find) again and do the following:
Put in the search box: 71C0 (That's a zero)
Put your device id in the replace box (Don't change it at all)
Hit replace all.
Save the file.
Now go back to the kext and go to /Contents/info.plist open it with textedit or whatever you want (I used Coda, you don't have to, just use a text editor.)
Search for IOPCIMatch
In the <string></string> tag, look for your id, your id is this:
0x Your Device ID, Your Vendor ID
Mine would be 0x94601002
If you find it, just leave the file and skip this step.
If you don't, put that id (0x94601002 (USE YOURS, NOT THIS ONE!)) at the end, make sure there's a space before it. Then save the file.
Now move ATIRadeonX2000 back into /Contents/MacOS (You will need to give your password).
Install the kext and reboot, you should have QE/CI!
If you don't feel safe editing the kext yourself, post your vendor id + device id + name of your card so I can make one to give to everyone.
Just realised this is in the wrong section, can ya move please!