Five squares, bottom one white?

[cjb]

Hi,

I have a 5d2, and when I'm recording video I see a fairly large blinking icon on the right-hand side of the rear (not top) LCD.  The icon is five squares lined up vertically, with the bottom square white and the rest of the squares grey.  It looks a lot like a low battery indicator, except my battery is full and my CF card is empty, so I can't work out what it means.  It flashes on and off slowly.

Does anyone know?  Sorry if this question is unrelated to ML; I've checked the 5d2 manual already, so I'm out of ideas on what's causing it.

[cjb]

Ah, found it -- it's the video bitrate/buffer warning.

Anyone know if there's danger in allowing it to stay at one square filled?  It didn't seem to progress to two squares.

[a1ex]

The risk of video stopping is high - try reducing the bitrate.