I notice it also causes the page width to increase, and your font is different to the rest. No idea what might be causing it though. Sorry. I initially assumed (wrongly I guess) that you were cutting & pasting from another text editor of some kind.
I wonder if BenDToy is right? Are you writing your questions in a Word document (or similar) first, and then copying it into the Answerbank window? Or, as I have asked before, are you changing the font yourself? Both of these may effect the way your posts appear.