Hi Shoe Box Zoo, [img]graemlins/happywave.gif[/img] welcome to Ironworks.
Here is a thread on the exact problem you have.
In case it's not clear from the thread, here's the process that should fix it (I hope):
1) Backup your saved games.
2) De-install the game and clean out the cache folder
3) Re-install the game
4) Install the appropriate patch - fileplanet has them all.
5) Put your saved games back into the saved game folder.
6) IMPORTANT! When you load a saved game, do not use one from the little area with the cave entrances. Use one from the area previous to that (e.g. from Wyrm's Tooth). Why? Because all the "attributes" of an area (random artifacts and random glitches) are set as soon as you enter an area. So if the re-install works properly yet you use a saved game with a bug/glitch in it, you will be overwriting the bug-free area with a buggy savegame.
Good luck. Let us know if it works out. Give a shout if you need more detailed assistance.