Whenever the resource under test contains an <object> tag, the mobileOK checker searches for images within that object tag with a view to extracting linked resources that respect the dreadful "Included Resources" rules defined in mobileOK:
http://www.w3.org/TR/mobileOK-basic10-tests/#included_resources

When the img tag within the object tag is not the direct child of the object tag, the mobileOK Checker runs in an infinite loop.

Ex:
<object width="120" height="64" data="image.png" type="image/png">
 <a href="[foo]"><img src="image.gif" width="120" height="64" /></a>
</object>

Code to fix is in the extractImages method in the ObjectResourceExtractor.java file. A "while" loop fails to update the element that serves as condition to exit the loop.