Powerbook screen looks washed out until reboot

My wife and I have separate users on our Powerbook. When I first login, everything looks fine. When she logs in and then I switch back to my user, the screen contrast changes after the user switch animation is complete. It's normal during the switch animation, then there is a noticeable flash and it looks washed out.

After that, I have to reboot to get the contrast back to normal.

My wife and I don't have anything in our startup folders, the universal options aren't changing, and I don't see anything weird when I run top in the terminal. Even if my wife logs out it doesn't go back to normal.

Does anyone know what might be causing this?

this is a very strange known bug in OS X 10.4 (Tiger). There seems to be some issues with colour profiles used when switching users. The way to fix it is as follows:

1) Browse to the following folder: /System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/CoreGraphics.framework/Versions/A/Resources/

2) Run the program named DMProxy

This will fix the problem until the next reboot. You could copy DMProxy to /Applications/Utilities to have each access in future. I'm sure there must be an easy way to get it to run automatically on startup, so I'll have a fiddle and post back later.

That does the trick.

Thanks!