First let me say I patched up to the 5.01 cumulative patch and all other relavent patches as outlined in the installation sticky. Everytime I go into the backdoor to the temple to fight all the bandits, the Lareth doublecross, the game crashes to desktop. Any solutions to this CTD?
This is the first time I've heard of this one. If I can duplicate it I will see what the cause is. You might need to post the saved game so I can check it out.
Find the files for the saved game (there will be 4 I think) in modules\saves. Zip them up, and post them here using the Manage Attachments button in the advanced posting window.
So I loaded up your saved game and played through the encounter. Other than getting my hat handed to me, it ran just fine. No CTD. I would suggest downloading the latest patch from the 5.0.1 thread and try it again. If that doesn't help a clean re-install is probably in order. It's something with your installation that is causing the CTD.