I was having an issue with dashboard widgets and pop-ins in the dashboard admin returning "0" instead of the expected content. Examples are the 'incoming links' dashboard widget and the 'google analytics' dashboard widget.
I spent some time activating and deactivating plugins and found The Welcomizer to be the plugin causing the issue.
Not sure how I can help you diagnose this issue, but seems there is some script loading in the admin backend conflicting with the normal operation. Perhaps a dynamic load of the necessary script only on the Welcomizer settings pages would be a better practice. Thanks!