No Event Firing When Opening Image From Lightroom?

All the buttons on my panel are disabled when there is no document open in Photoshop.
As soon as a document is loaded the buttons become active because a load even is fired in Photoshop.

In Lightroom when you choose “Edit In Photoshop”, the document is handed over to and opens with Photoshop but Photoshop doesn’t appear to fire an event which means the button on the panel don’t become active.

Is there an even firing somewhere which I might be missing ?

I have just tried this with Adobe Bridge and an “open event” fires in Photoshop, so the issue appears to be when you select “Edit in Photoshop” from Lightroom