I run the Nvidia 182.50 driver for Vista Ultimate 64bit - the left image problem doesn't appear running my Vue 7.4 beta - so not sure, if this is a graphics card driver or operating system issue.

The metacloud preview images on my Vue 7.4 beta are messed up the same way, like shown in the right image.
Looks like this has to be fixed by the programmers ... at least the metaclouds are loading correct.

triangle - yes, the light color selection in the Light-Tab is turned off using spectral atmo model. Looks like this was done on purpose, since with spectral atmo selected, it never had an effect anyway.
If you want to change overall sun and light colors using a spectral atmo, you can use the 'ambient light color' box in the Light-Tab in combination with the 'sky color' box in the 'Sky, Fog and Haze' Tab, giving you even more diversity in atmo lighting colors.