weird problem with finder

hello all,
I've looked in the archive, and as far as I can see no-one's posted this problem.
I'm running 10.2.8 on my Titanium powerbook, and just ran the last security update (september 04).
since then the finder has gone bananas.
when I open a new window showing the computer (i.e. network icon and hard drives) there is only a network icon, unless i switch to list or column view.
and if i try to move, copy or delete a file i get that annoying rainbow spinning wheel that doen't end - even after an hour. so I have to relaunch the finder.
it's the same if i log in as root, so it's nothing to do with the user settings, and when i created a boot cd to run drive 10, the problem still occurs running off the cd.
does anyone have any clues? I've deleted the com.apple.finder.plist file and rebuilt it on restart, and no luck. i've also tried verifying and repairing permissions.

thanks in advance.