jeffqi,

 
Yeah it's due to a restriction in SAFARI which doesn't support HTML editing.

We need to wait for the next version of Safari.

http://www.appleinsider.com/article.php?id=619

"A new version of Web Kit to be included with the Tiger release of Mac OS X will support HTML editing, DOM level access, and a new Safari plugin-model, reliable sources tell AppleInsider."

 

"The new version will deliver HTML editing features that will enable developers to create editable text views containing HTML. Developers will be able to use these features to replace text and manipulate the document text and attributes, including CSS properties. According to company documents, the editing support is not intended to provide the features available from professional HTML editing applications, but instead is aimed at developers who need to display and handle the basic editing of HTML content."