"corrupt" widget wp_options entries: duplicate widgets

Hi,

bit of a weird one which I have unsuccessfully searched for solutions here and elsewhere…

See screenshot of the Appearance/Widgets page >>> http://artshine-dev.oneleafdesign.com/resources/ads-right-widget-screenshot.jpg

As you can see there is a duplicate of the Ads Right widget and an untitled widget. The first Ads Right widget works fine but last Ads Right widget is non-functional i.e. does not display in the relevant pages.

I have 3 custom widgets registered in my functions.php file and Ads Right widget is definitely only registered once. See http://artshine-dev.oneleafdesign.com/resources/functions-php-screenshot.jpg

I believe the problem arises from the entries already stored in the wp_options table and I would like to be able to identify and clear up the records. Unfortunately I am not in a position to just null all the relevant wp_options records as I have lots of complicated html in the widgets.

Switching to TwentyTen theme just dumps all the widgets in the inactive section as expected.

Any hints?

thanks and kind regards,
Mark