There are some updates to Sky Writer. The tool is now at Version 0.12 which has the following changes:
Version 0.12 (2011-03-10)
Added Gamma Spinner to control output gamma of rendered bitmaps
Added some error checking to alleviate a few uncaught exceptions
No longer opens the material editor upon render
Fixed bug when picking existing Sky Writer Helper that had a resolution of 4096 (though in reality... that resolution is WAY OVERKILL in current engine)
The gamma change is important. The gamma spinner defaults to 1.0 with new sky helpers unless the Exposure Control is set to mr Photographic Exposure Control... in which case it defaults to 2.2.