Ok, this is so very weird. I cannot understand why this is happening - way over my head. I'm hoping to God someone can help get to the bottom of this with their knowledge of Javascript and how it works in the CMS (though I'm pretty sure it ain't gonna happen tonight. I've got a nasty bullet to bite tomorrow!)
I'm using ModelAdmin to manage 3 classes - Sector, Category, LibraryItem (each managed in their own tab of course). Sector and Category CMSFields are pretty much default scafolded. The LibraryItem's CMSFields have a number of DOMs in - namely Image, File and ManyMany - replacing some scaffolded fields.
I've only just noticed this happening, but can't think what would cause it:
If I load my ModelAdmin tab in the CMS and straight away open up a LibraryItem, all javascript for all my DOMs is broken. This happens silently in Chrome, I get a useless debug window in IE.
If, however, I open up one of the other items first - Sector or Category, then open up a LibraryItem - all Javascript is working nicely.
Please, please help.