Cant maintain monitor calibration

I've been using my computer here at home for many years and since I do a lot of photography work I have always kept my monitor color calibrated using a "Pantone Colorvision Spyder" unit. It does a great job and my screen always looks great. Up until now I have been the only user on this computer. My wife wanted me to set up a Facebook account for her so..... first I created another user account on my computer. So when she wants to use the computer she signs in on her own user account. When she is done she signs off and then I can switch users to get back to my settings and my user side.
Well...here is the problem. When we switch back to my account I lose my monitor calibration and my screen goes WAY too bright and I have to hook up my "Spyder" and re calibrate. I have tried to go into my display settings in my control panel and it shows my last saved calibration as the default setting but it will not go back to it even if I click "apply".

Any Ideas on what to do about it. I should be able to have several user accounts......shouldn'​t I????

I have tried to calibrate the monitor while in both user sides but that does not work either. This is not a monitor problem as it only happens when I switch user identities.

I'm running windows XP

In a test ,alt clicking the Spyder icon in the taskbar gives an option of 'Calibration off' 'Calibration on' and a test restarting the video card service turned the calibrated display off even though my software said 'Calibration on' , switching off then on again brought back the calibrated display.

I honestly don't think you should need to calibrate the Display everytime , but I do believe losing calibration its related a break in the video card service while switching users and possible work around giving the Spyder software a restart.

Did you use fast user switching or go through the log off, log on route?