#8 Classes not found initially

[Anonymous]

Would be same effect than in issue 1555947.
1. I load the clean-ajax-boot.js in the header of an HTML (script include)
2. Afterward I add another script on top that handles the registration of dnamic content panels on a HTML page (just code, nothing executed, yet)
3. Within the body, I register the panels (7) I get a js error stating:
'Message' is undefined js_intra_update_handler.js, line 573 character 5
Code of error:
var ajaxMessage = new Message();
4. Hitting refresh in the browser does not cause problem afterwards as the JS file previously missing is now in IE cache
I tried 4.3 and it is even worse.

is the only conclusion that all the panel registrations must be delayed to wait for the rendition of the full body ??

many thanks