Struggling since the last update

Question

I've not had any problems with Safari since purchasing my IMac = in fact in fact it's my browser of choice. But since the last update it's horribly laggy - as I'm typing this message, the text isn't appearing until a second after I typed it. I click something and it's a second before it actually clicks... you get the idea. I don't have any addons installed in Safari, it's just a basic installation and I had no issues at all before the latest update.
Frustrating.

Answer 1

First, Safari 4 requires Mac OS X 10.5.7 to run, so you need to update your profile.
Did you use Disk Utility to Repair Disk Permissions before and after you installed Safari 4 (or anything else)? If not, quit all applications and do that now.
Then, try this:
Go to ~/Library/Caches/com.apple.Safari and delete the contents of that folder, then use Get Info to Lock the folder.
Go to ~/Library/Caches/Metadata/Safari and delete the contents of that folder, then use Get Info to Lock the folder.
Go to ~/Library/Safari and delete these files:
History.plist
LastSession.plist
Restart Safari and see if things improve.