[support] problem with finishing page loading?

Hi!

I have a problem that I find difficult to describe, let alone finding documentation: Any hint appreciated! on one of my sites on a multisite drupal 6.8 I have a problem when I want to edit or add a node. TinyMCE doesn't load and collapsables don't open. The icons don't appear. So, I cannot change Input format or any of the settings at the end of the page.

It is not a problem that depends on the theme. It is not the drupal core since the other sites work fine. I noticed however that in my other sites it looks the same before the page finishes loading for about a second or so, when TinyMCE is not yet active, so I assume I have some problem that prevents my edit page from completing the page loading.

Any ideas? Any tips where to look for help?

thanks!

maurice