Latest 3.1 update seems to break Views' admin AJAX

Updated the module today and now any new Views that get a VSX attachment cannot be edited via AJAX pop-up (e.g. clicking on 'Settings' in 'Format' for 'Slideshow' in 'Block' or 'Slideshow' displays).
Those AJAX pop-ups work ONLY in 'Attachment' display - in all other displays clicking on any settings results in a throbber appearing for a sec and then nothing comes up. Clicking it again often results in an almost WSOD (with a lot of text from AJAX call on the screen - see attached image); if in, say, 'Format' instead of settings we click 'Slideshow', the pop-up will come up but on applying the page will again turn to garbage as above.