I have the same issue, however, ctrl+u doesn't show up as a space at all. It shows up as something unseeable. As in, it's zero width. So if you have two .<underline><underline>. if your cursor is before the first ., you press right, it moves past the first period, if you press right again, it doesn't look like it has moved. If you press right again, same as before, it doesn't look like it has moved. However pressing it again will make it go past the second period.
ctrl+u does work, it's just displayed as a 0width( and height? ) character.
