How about if using other browsers? I don't think Internet Explorer is even available for iPhones.
If you want to
make paragraphs or create a line space just put this bit of code <p>
between any word or sentence where you wish to create a break.
However you must first have ticked the 'Use HTML editor' box on your profile page.
This method works for me even though the HTML editing menu never actually appears when I click on the HTML icon at the bottom of the message box regardless of whether I use Firefox or Explorer.
The other thing I have to do before being able to type anything into a message box is click "Preview' then click "Back to edit mode".
I am using Windows 8