slowdown after OS X install?

I installed OS X 10.5.6 from a USB stick on my AA1 a110 512/8G and everything went peacy. Even the standard builtin wifi card showed signs of life (see methods below), though ethernet didn't work. But then I thought I'd update to 10.5.7 with Apple's own updater. It updated alright, but then it went into a reboot loop. The first broken boot, it made a really nasty loud beep and then started booting to the gray Apple screen, going black and repeat. By then it was way past my bedtime, so I tried to get some sleep and I think I shut it down by pressing and holding the power button.

In the morning, I thought I'd reinstall, but then it appeared to freeze at the bios screen where you can press F2 or F12. Pressing F12 changed the text to something like: "yeah, I'm loading the boot order menu now. just a minute". But that took 15 minutes, maybe half an hour. I was really scared that it had died or had some kind of BIOS freeze. Fortunately, I chose to wait.
I reinstalled (takes about an hour), did the things mentioned below, but Mac OS X didn't feel as snappy and fast as it did the first time. Even booting is slow now. Any ideas? Did Apple's 10.5.7. combo update do something to my BIOS?

I'm still working on it and intend to use the iDeneb 10.5.7 update. Maybe that'll do something.

Methods:
- made bootable USB stick by following this:
http://www.insanelymac.com/forum/index. ... pic=154853
(note that I used chameleon 10.0.11, even though it is at version 2. v2 wouldn't install for me)
- installed 10.5.6 by following this:
viewtopic.php?f=14&t=11796&start=0
(note that on my machine, I couldn't get ethernet to work)
- installed atheros driver by following this:
http://www.insanelymac.com/forum/index. ... pic=162189
(doesn't work yet, but looks promising)
- turned off spotlight by deselecting all in the preferences panel and dragging the disk in the privacy field.