Displaced answers on the widget multiple choices answer line.

Hi all

I am writing a Math book at the moment and I wish to use the multiple choice widget. I have used this successfully previously but when I try to enter a surd value (a value with the square root symbol) I find that on screen (in the iBooks Author), and in the PDF export the answer and the answer letter line up OK, but if I render the book and / or view it in preview mode on my iMac, iPad or iPhone the answer is displaced down to the next line:

Example

Answer 1:

answer appears here

Answer 2:

answer appears here

But in the PDF version the answers line up OK.

Answer 1: answer appears here

Answer 2 : answer appears here

I hope this is clear, can anybody help please?

Many thanks

Martyn