Just install the Snow Leopard DVD in the drive while your Mac is running. Double click to "Install" Snow Leopard. When it's finished, you'll be back to just 10.6.0. Everything will be saved. You're not doing a full restore.
After you're finished, go here:
http://support.apple.com/kb/DL959 to update the 10.6.2 Combo. When that's finished, do a software update, but make sure to UNCHECK the 10.6.3 update. Keep the 10.6.2 Combo file in your Documents, or somewhere you can find it just in case you need it later.
When it's all finished, you should be back to normal. So far I'm not having any issues with Safari 4.0.5 running on 10.6.2. I'm about 100% sure the problem comes from 10.6.3, NOT Safari.