Scrabble app, Dictionary feature. Try to type CAT, for example. _CAT appears. (The _ is always auto inserted before the intended text.) App recognizes the text as _CAT. Try to remove the _, and the entry becomes CACAT, and that's how the app recognizes it. This fault does not happen with other keyboards, so it is a Swiftkey problem. Same problem with Swiftkey X and Swiftkey X Tablet. Relatively new bug, perhaps since around first of March 2012.