Steps to reproduce the issue

Create or edit an article in the back end. Select an image for the Intro or Full Article Image. Insert the image. Mouse over the preview icon: the image will appear the first time. If you mouse out and back over, it will not appear and continue throwing javascript errors.

Expected result

The preview image should appear each time you mouseover the preview icon.

Actual result

The image only appears the first time after you mouseover the preview icon.

System information (as much as possible)

Linux, Apache
Joomla: 3.3.0-dev Development [ Ember ] 6-March-2014 14:30 GMT
sql: 5.1.73
php: 5.3.28
Chrome browser: Windows 33.0.1750.154 (Official Build 257193) m
Firefox browser: Windows 27.0.1

Additional comments

The error comes from both mootools-core.js (line 105) and the current page (/administrator/index.php?option=com_content&view=article&layout=edit) on line 312 (img.src = "http://website/" + value;)

This issue was discovered only on the 3.3 dev version. Previous 3.2 versions do not exhibit this issue. It is template independent (occurs in both hathor and isis).