My monitor (LG W1934S) has a greenish cast. To compensate, I increase a bit the red channel.
This has been fine for a long time under XP.
Now, under Win 7 64, after I've upgraded the video driver for the next to last version, at boot time the increase in red channel is not applied anymore.
If I make any change in the Intel Graphics and Media Control Panel the correct value is applied at once (for instance, using the ctl-alt-up keyboard shortcut - nothjing changes in the screen but the correct red value is apllied).
Upgrading to the latest video driver version did nor change it.