iOS 6 email signature entry screen display issue

I've updated my iphone 4S (32gb) to ios 6 and proceeded to add signatures to some different email addresses. The first one went fine. But when I tap to start adding another one, the screen changes and the entry box appears to disappear and my input appears to move down to the next email account signature. I can exit and come back in and see that the line I entered did get into the correct account. But when I attempt to enter another line the same thing happens. Very disconcerting. I also notice that while inputting a third line the text is outside of the white input area into the blue area - it still saved fine, though. I'm a programmer and can handle this - but non-technical users might freak out.

Tapping other signature input areas may or may not cause the white entry area to disappear - I cannot discern a pattern. Scrolling up and down seems to correct the display temporarilly.

The signatures do appear to work fine once entered as they do appear when I create a new email.