funny, i was just uploading a fix for this. It's a known issue, my email 30 seconds ago to a microsoft/unity team:
"i just tested it... nope it does not work, it returns flipped info. I have to use the sample code I gave to make it work the same than my android."
in short, i solved it by using a workaround. Microsoft should be releasing the update tomorrow. And hopefully they give me a "real" fix soon.