[quote name='Ed Welch' timestamp='1346244428' post='4974406']
If I call glDrawBuffer(GL_NONE); the error goes away, but then nothing gets drawn to the frame buffer.

It seems some graphic cards require that you call glDrawBuffer(GL_NONE) if you have a FBO and only want to update the depth buffer. You say nothing gets drawn, by which I suppose your depth buffer wasn't updated?

Did you have to add a color buffer to get it working?
[/quote]
Actually, now that I check, the color buffer wasn't needed. The real problem was caused by the near / far values in the perspective matrix (at least I think that what it was)