DSLRUsers.com

Just released from Nikon USA, updates for D80 and D200 in both Windoze and Macca formats.
Remember and charge those batteries before updating, and please READ the instructions carefully!

This firmware resolves an issue which, in rare cases, causes the battery indicator to blink whilst shooting regardless of the level of charge in the battery.

Nikon Support & Downloads

Yep, had that issue a few times..

Haven't had this problem yet - Is it that common?

Very useful, kind presumed updates would've dried up after V2.00 for the D200. I don't know if this is a symptom or just 3rd party bats, but I had all of the following recently in coolish weather: battery level blink, with moderate slow shutter the viewfinder would black out and camera freeze, Err displayed on LCD. I have MB-D200 grip with 2x Phottix bats. At the time I thought - 'ah the downfall of 3rd party batts', perhaps their current is inadequate as both batts had good charge according to pwr meter.
Mark