The sun seems to disappear in storms if I center on it.

I've turned only a few degrees between both shots.
http://home.arcor.de/famscheffler/ven/stormsun/dump0091.png.jpg
http://home.arcor.de/famscheffler/ven/stormsun/dump0092.png.jpg

the graphics card is a radeon 9550 running under linux