2 monitors. Different colour temps

Hi,

I have a dual monitor setup. Both monitors are identical and were bought
together. But they display colours differently, even though the settings
are exactly the same. And I can't seem to get rid of this problem, no
matter how much tweaking of the manual colour ballance I do. Can you help
me, please?

Equipment:

2 x Iiiyama VM Pro 413 17" HM703UTABK
Matrox P750 (latest BIOS and Drivers)
Windows XP SP1

Thanks,
Jack