If you are using a sun or infinite light, the sky dome is shading it, in other words you are working in the shadow of the sky dome.  If you want to use the sky dome, use an infinite light pointed straight up and set it to illuminate only the sky dome.  The scene would have to be illuminated by an infinite light set to ignore the sky dome (illuminate everything except).

Depending on the sky dome (I have used several in the past but don't bother generally any more) you may have to to into the shader and use the map you want as the color node.

I generally use realistic skies combined with a sun light for outdoor scenes.  You have to turn the sun light on in render settings, but usually I leave it off until rendering as I don't want a recalculation of lights for every quick look in the assembly room.

I would need more info regarding why a sky preset doesn't work with a poser scale (by which I assume you mean small) scene.  I have not experienced problems with this.

If any of this doesn't make sense, let me know.

Klebnor

Lotus 123 ~ S-Render ~ OS/2 WARP ~ IBM 8088 / 4.77 Mhz ~ Hercules Ultima graphics, Hitachi 10 MB HDD, 64K RAM, 12 in diagonal CRT Monitor (16 colors / 60 Hz refresh rate), 240 Watt PS, Dual 1.44 MB Floppies, 2 button mouse input device.  Beige horizontal case.  I don't display my unit.