I was following blengines tutorial for rendering with radiosity. I got as far as the last step. I have claculated it, but now I cannot get a rendered image. When i press render I get an almost black image with faint outlines of the objects. Look at this screenshot to see what I mean: http://forums.interestingnonetheless.com/uploaded/emtilt/radprob.jpg
The rendered window is in the lower righthand part of the image.
What am I doing wrong? Any help is appreciated, because I have a real project I would like to try rendering this way.