Steps to reproduce issue:
1. fire up Liferay 6.1 CE Server
2. log in, using FF 27
3. add an asset publisher portlet
4. choose "Add New" > "Web Content"
5. click the configuration icon next to "Template: None"
6. fiddle around with resizing the popup window
The window got stuck in a state where I could not apply the resized view, and could not cancel it either (see attached screenshot). So far I could not reproduce this, will provide more information when I discover what exactly triggered the resize bug.