Re : Error: Permission denied to access property 'steal'

I can get this error showing in Firebug consistently if I open a new tab somewhere else, like from the Twitter site, and then change the URL to a javascript MVC project.

Error: Permission denied to access property 'steal' <url>/steal/steal.js  Line 2057

1. win.top.opener.steal && win.top.opener.steal.options.instrument) ) {

So, is the error really just that steal.js doesn't have access to win.top.opener? Which makes sense if the opener was a different site.