I have the same issue with a C400 WinXP SP2 image I'm creating to deploy to about 60 laptops. This is my exact behavior which I can reproduce 100% of the time:

I boot the laptop and login. I attach an external video source (monitor or projector). I right-click on the desktop, select Graphics Options - Output To - Intel Dual Display Clone. The monitor now gets the output, and the laptop image shifts about 1/2" to the right with the right edge showing up on the left. The laptop image also shimmers or shakes slightly making it difficult to read. Repeating the process to select the Intel Dual Display Clone, and the laptop image corrects itself. (Using Fn-F8 has the same results, but you end up cycling through other modes as well.)

Then, after shutting down, I remove the external video source and boot only to the LCD video. After logging in the screen blanks briefly and the image shifts to the right again.

I have tried numerous techniques to fix this and nothing has worked yet. Have you had any luck?

called dell, went through the troubleshooting steps with them, they sent me a new lcd for the laptop, hooked that up, so far the person using it has not come back to me, so i am assuming that he has had no problems with it.  Luckily the machine was under warranty.

Unless Dell made a hardware change in the replacement LCD's, I doubt that will fix the issue in my case. I have tested this in 3 different C400's and the results have all been the same.