I have just upgraded my machine from Win 8 to 8.1 preview. Running Windows Live mail,  when I open an email to read it the text size is normal - 12pt. As soon as I click on reply, the text size shrinks dramatically - it still tells me it's 12pt but it looks more like 6pt.

I can't find any reason why it is doing that. I have uninstalled and reinstalled Mail, but it has made no difference.  It was working fine on WIn8. Any suggestions?

Thanks