Yep, been there, done that. I also had terrible intermittent trouble with auto white balance on one of my cameras. Usually it would be fine, but sometimes I'd get some really wonky results. Same problem: the D2h (and the D2x) has a white balance sensor on the top of the prism, and a couple of my hats were blocking most of the light getting to them...

And of course, with either of these problems, if you start tinkering with the gear to try to isolate the issue, it will inevitably stop as you are changing the circumstances...

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Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!