**USE AT OWN RISK, IF YOU DO THIS AND FRY SOMETHING, NOT MY FAULT, and DON'T ASK ME FOR HELP, I WROTE THE INSTRUCTIONS FOR YOU**
I have a 15" Powerbook, 1.67 Ghz. (not the HD screen model, the one before it). The Airport Extreme range really really sucks in it. I can't go to the other side of my house, and have it work.
I am also currently in a hotel where, apparently, the WAP is really far away from me or something, because I have one bar. So, I googled solutions.
I saw a bit about reset-ing my PRAM, so I did that. (Turn off computer, hold down Command + Option + P + R, and turn computer on, hold buttons until the Apple boot sound, and release). This will reset your NVRAM/PRAM and may help. I did that. I don't know if it helped at all, but I still only had one bar.
I saw a bit about reset-ing my PMU, so I did that. (Turn off computer, unplug, remove battery, and then press and hold the power key for 5 seconds -- i did it for 10.) This will reset your PMU. I did that. I don't know if it helped at all, but I still only had one bar.
So I googled some more. I found a solution online, that I am willing to share:
Hold down the Option key, and click on the AirPort icon in the menu bar.
select About AirPort...
The Apple Framework version is what you are looking for, mine was 421.13.0
However, the current Intel Framework is 426.1.0
That's quite a difference, so I thought to myself, where can I get the 426.1.0 Intel framework. OSX is universal binary, so that shouldn't matter... right? So this is what I did.
I went to Apple.com -> Support -> downloads, and I downloaded the 10.4.5 INTEL update. Now, after you download it, Apple is going to automount and run this thing, which, obviously, since your on a PPC, it can't do. Right click on the package and select "Show Package Contents".
You will see a file called "Archive.pax.gz".
Double click on it. It will untar/gz itself onto your desktop.
Shut off your airport, by clicking the icon in the menubar, and click "Turn Airport Off"
Open Terminal, type:
mkdir backup-framework
cd /System/Library/PrivateFrameworks
sudo mv Apple80211.framework ~/backup-framework/
sudo mv ~/Desktop/Archive/System/Library/PrivateFrameworks/Airport80211.framework/ .
(notice the period at the end, for move to current directory)
This will move the Intel 426.1.0 version that you just downloaded to your Airport80211.framework folder.
Now type:
open /Applications/Utilities/Disk\ Utility.app/
This will lauch Disk Utility (or you can go to finder, Applications -> Utilities -> Disk Utility) and click on "Repair Permissions on Disk" or whatever it says. So it will set all that stuff you just put there, as root. (As well as correct whatever else is wrong with your system).
Restart System.
Turn Airport back on.
Now, I noticed a couple things:
1. My computer booted in like, 2 seconds.
2. My Airport now had 4 bars, sitting in the exact same spot where I had 1.
Driver? Don't know. But it worked for me.