Sometimes the baseline of text in a TextEditor will shift by one pixel when it goes into edit mode. This is clearly visible in IntroJucer project settings edit controls.
In case there is any doubt or confusion, here is the problem:
[attachment=0]baseline.gif[/attachment]
From the looks of your animating image, it seems the text-box border highlighting is the culprit.
Can we please fix this eye-sore?