For example there are two different domains: domain A and domain B:

Domain A has an iframe which loads a domain B page with a JavaFX application emmbedded in it.
Loading of JavaFX application is never starts becuase of the javascript error written below.
As far as I know this is only a issue for Mozilla Firefox version 7 and 8(current)...

The javascript error is:
Permission denied to access property 'execScript'

And of course it is followed by an error:
dtjava is undefined

This is an importatn issue since applications on social platforms is loaded in iframes. And firefox is one of the major browsers.