Hey Beery, I think Cpt-Blaubär's right about the ATI sun problem. I've seen some other guys talk about it already, but here's how my sun looks on a 7800gt nvidia:
It seems like some or all ATI cards aren't rendering the bloom around the sun properly...
Funny enough, my sun loses the bloom around it when I line it up behind the edge of my sub's deck...
It's great to hear that you're starting up a mod for SHIV, though... I've always been a huge fan of the mods you've done for other games through the years.