Here's an interesting, if somewhat odd bug found with Samsung Windows Phones: if you send a photo to any device with iOS 4.2, upon saving the photo, it renders it unreadable. So you can preview it when attached in an email (like above) but if you save it to the Photo Library, you get the gray JPG image and no pic. And indeed, we replicated the problem ourselves.
A simple work around is to use a 3rd party editor like Thumba 2 or Pictures Lab--those programs will alter the JPG header data in such a way as to render this (ba-zing) a non-issue. Of course, that's no excuse for Samsung (or Apple) to not take a look at this and address the issue for those iOS devices and Samsung phones.
Further discussion can be found in the Microsoft Answers forum. Thanks, Not Shred, for the tip!