When WebView is in edit mode mode, <br> tags are inserted into the document when the Enter key is pressed. Most modern browsers, including Safari 5, IE 9, Firefox 4, and Chrome 11, insert <p> tags when Enter is pressed. To reproduce, visit this page, position the caret in the middle of the word "paragraph", and press Enter:

http://html5demos.com/contenteditable

This breaks RichTextArea, which uses WebView internally and also expects paragraphs to be inserted on Enter.