Sky colour/brightness change on render?

[k00k]

If I render out my scene just as a single frame test render, the sky looks spot on. As soon as I render it out to a targa sequence, the sky changes brightness and becomes extremely bright, bordering on white and far too much glare. Anyone else had this problem? I cannot find a solution, and its totally annoying me!

I'm using Max 7 and DS 2.5.

cheers
k00k