I think the colors might be a bit too dark, which causes the contrast to be too high.
Try a brighter blue and a brighter green (not trying to make WrongPlanet look-a-like here!). (Especially a brighter blue)
I just have an idea that it might seem more welcoming and comfortable that way. But I really like the dark background!
Oh... and there's a contrast problem more...
NT/AS Discussion -> Click a subject -> Click browser back
Notice that the blue "visited-link" doesn't work on the green background.
Overall I think it looks really nice.
Okay.... Right... I've done another few tweaks to the colour and doesn't look so deadly bright anymore..