Thanks for posting these great examples.  I wanted to let you know that the Windows Live Photo Gallery team and Microsoft Research (creators of ICE) talk all of the time.  We collaborated on the first version of WLPG stitching.  We are aware of the issue that you point out and as you have noticed we have worked hard since last year to improve on the exposure blending.  The WLPG team will have more to say about this when they ship next month.