I can't help too much except to offer that JPEGs support lossless image rotation. I use the feature all the time with Irfanview. My Sony DSC-U50 can rotate its lens 180 degrees so I can take self portraits with a friend. Then I use Irfanview to losslessly rotate them 180 degrees back.

Having this automatic would be better, but I'm pretty sure the Windows program does it losslessly too... I simple test of file size should let you know.