updated 04:14 pm EDT, Fri April 26, 2013
Bug existed as far back as December, documented on Apple forums
A strange bug in Apple's iMessage service is manifesting itself. Messages of a certain length are rendering the final word of the text invisible (but still present) following sending the message to both sender and recipient. Two phrases induce the bug for some users -- "I could be the next Obama" followed by a space causes the display oddity. The phrase "the best prize is a surprise" also causes the odd display problem.
Perusal of the Apple support forums show that iPhone users have been posting about the problem since December. The problem doesn't seem to manifest itself on the iPad, iPad mini, or OS X version of Messages. Copying the text out to a different app displays the entire message, so the data itself is being sent to and received by the recipient properly.
Some users report upgrading the iOS device to version 6.1 of the operating system fixes the problem. Twitter has a thousands of users attempting to reproduce the problem with near 100 percent success. The problem at first glance appears to be a miscalculation of display length, with the iOS calculating that it needs less space in a bubble than it does, given variable width characters.
MacNN tried several mixes of iOS revision and hardware, and could not reproduce it in iOS 6.1 or on the iPad at all. The problem did exist, however, on iOS 6.0 on the iPhone 4 and 5, and a fourth-generation iPod Touch.