Luckily I came across this great starting point provided by the guys from nettuts.com

Check out the tutorial which includes javascript to detect the users browsers and the orientation of the iPhone to serve up the correct stylesheet for either portrait or landscape view.

http://net.tutsplus.com/misc/learn-how-to-develop-for-the-iphone/

Basically it is a Firefox issue, clashing with WordPress.com’s implementation of the TinyMCE rich text editor. Javascript is causing the copied image and link in the clipboard to be changed to relative urls instead of absolute. i.e. src=”http://anthonylrivera.net/images/image.jpg” becomes src=”../images/image.jpg”. Which then breaks the images when the post is published. I have found a tweak in firefox to correct the actual image source from being changed.

In the about:config section of firefox, a setting called dom.disable_image_src_set when set to true, will stop any javascript from altering images on every page. This then makes certain Dynamic Image plugins not work, but only for that end user.

This still leaves the surrounding anchor tag modified though. Still searching for a solution. If you know anything about this please drop me a line…