I think you might be hitting a known issue here – in the first instance (this might not work but is definitely worth a shot) can you edit your wp-config.php and add:
define('WP_SCRIPT_DEBUG', true);
(If there is already a line in there relating to WP_SCRIPT_DEBUG but set to false, please just change it to true.)
Does that help? If not don’t hesitate to shout back and we can look at other options.
Thank you! – I tried it and I got a bunch of error messages on my site, so it appears that it needs to be set to ‘false’ for other purposes – other ideas?
Well, we hopefully have a maintenance release which will be unleashed imminently, if you can hold tight a little longer it would definitely be worth seeing if that helps.