I can't find the bugzilla, could you give me a link? I wanted to search there first, but couldn't find it.
At least I remember reading about it here, if my memory serves me well.
EDIT: Other GL games are not affected, and playing with overbrightbits in oa helps things.
Openarena does not appear any darker on my system either (HD3450, Ubuntu 9.10, radeon libdrm & drm from a couple of weeks ago, mesa from a few days ago).
We're not saying there's no problem, just that it's not showing up as pervasively as you might be thinking.
I know, and I can't find a bug report either. It could be something very strange, but I'm quite sure that I didn't mess with any game settings.
I've found a number of things on the internet relating to openarena being dark because of issues with hw gamma on certain chipsets, but nothing relating to radeon drivers.
I'll see if I can localise better what caused it.
As of 0.1.60, Heroes of Newerth requires ARB_pixel_buffer_object, which the r600 driver doesn't have.
The workaround is easy, I just do
xgamma -gamma 1.8
before I start the game. If you have multiple displays you may need to use xrandr instead. Using that you need to specify display and give r,g,b, also < 1.0 is brighter .