Screenshots of what you're doing.

morfar: i wondered why only part of the left wall gets light of the sun. and why doesn't e.g. the wall above the ammunition get light from the sun?

Oh, that. That's because the sun is not directly shining on that wall.
The sun angle is exactly 270 degrees, so the flat wall is not hit by the sun.
The general lighting looks good in-game, I see why that screenshot may be fooling you.
But I still think this is correct behavior. Q3MAP2 could support better sun lighting if it knew how big the sun diameter was.

what i meant with the hdr.... when you have a light in the map and enable hdr or bloom, it gets a glow around it. to make sure we talk about the same setting, look at this: http://www.xnainfo.com/file.php?file=101

and if the glowing object is partly overlapped by another obejct, the glow "overlaps" the object. does this also work with light sources in the skymap? because on the second screenshot it doesn't look like this on the left edge of the wall.

i hope you understand what i mean

Sounds like an engine feature more than a skybox feature
DP's HDR is not real HDR, but just bloom with better quality.

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oo cool morfar. Im glad you have the hang of things. Did you get some camera angles a slightly different shade to the rest and you had to correct them in GIMP in terragen?

I think 2048 is needed because it maintains zoom detail when in zoom, unlike 1024

No, I did not correct anything in GIMP. This sky did not need that. (GI disabled).
But I have an other sky which is clearly affected by Terragen 2 bug(s), shadows get misaligned between images, and I can see tiny tiny seems between images. fov is correct, and GI is disabled, so I don't know why.

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