mail search results are not in chronological order.
when I search for mail the results in iOS7 aren't in chronological order anymore. Both on my iphone 5 and my iPad 2.
iPad 2, iOS 6.0.1
I find that any messages that are flagged go to the top before Mail starts sorting in chronological order. I assume that's a "feature" and not a "bug." Is that what's happening for you?