Is there any going back??

Hello people!

First of all, please forgive me, I have probably done something stupid due to a total lack of understanding and blind, careless fiddling around! I will try and explain the situation as best I can, but I really can't remember too many details. If that hasn't put you off already, please read on.

I had got my AAO set up nicely, running well and tweaked to my liking - advanced desktop, desktop switcher, Firefox 3, Flash 10, Open Office 3.0, Compiz, Emerald, VLC, XMMS, Ktorrent, Kdocker, Wine, Gimp, Login screen, Xscreensaver, hplip printing fixed... Then I went and installed a load of updates from Xfce Menu > System > Software Updater. I wasn't sure if this was a good idea at the time but I did it anyway. Now I know, because I things aren't working well now. A few examples:

• File manager doesn't run - it blinks on the screen and disappears. Terminal output reads: "segmentation fault"
  Alt+F2 no longer brings up 'Run' dialogue
  Compiz doesn't seem to have any effect
  The title bar of any window is missing
  Emerald themes don't have any effect
  Many of the menu items don't work icons are missing too - Settings like Desktop, Display, Settings manager, User interface, Window Manager etc.
  Sessions and startup settings doesn't work - NOTE this never worked: "no such plugin - sessions", but started working after updating. Now it doesn't again. Btw, when it did work I set it to automatically save session but DIDN'T set "Load GNOME components" or "Load KDE stuff" - Maybe this means something.
  Background manager isn't working
  KPowersave isn't running in the panel
  Panel buttons/icons have changed

the list goes on

I have a couple of questions;

• How can I force the 'Session and Startup Settings' plugin to run so that I can set it to load KDE and GNOME components - I'm making an assumption that these things aren't anymore which is causing other stuff e.g. Compiz to not run
  
  Is there any going back? Can I roll back, uninstall updates or reinstate the original XFCE items? I'm trying to work out whether it's worth trying, or to lose all my good work so far and rebuild Linpus from the recovery disk.
  
  Is there a log somewhere so that I can identify what was updated? Is there a repository somewhere for me to obtain the original packages (I would need a list of the original packages)?

To give you some idea of the updates that were applied (if you're not bored yet!), there were things like:

• xfce-utils
  dbus
  hal
  lots of lib-things
  network-manager
  kpowersave
  pulseaudio
  thunar
  terminal
  xterm
  bash
  x11/xorg stuff
  amongst other things (adobe reader / flash...)

This is a cry for help really, from someone who doesn't know too much what he's doing. I'm sorry it's a long post and there's probably not an easy way to help me, so if there are no replies I will get the hint! But if anyone can make any sense of this and offer some suggestions - answer the first question at least - I would be extremely grateful.

Cheers, James :?