I have the exact same issue, but have been unable to find a solution searching the forum or internet. tried firmware 1.02, 1.04, and now 1.05b5, but it's still an issue... as soon as the lens receives direct sunlight it progresses from slightly overexposed to unviewable white image.
Would love to know if there was actually ever a solution to this thread/issue...
I've tried adjusting the brightness, contrast, and saturation (Setup - Image Setup)