[wp-hackers] after 3.2 upgrade cannot set images as featured or insert

[msacks]

I just upgraded to 3.2. Nothing else has changed.
Now I can upload images fine, but when I try to insert into a post or
"use featured image" it just hangs.
Is anyone else having this problem?
Is a bug report in order?

Response headers http://www.pastie.org/2180743

HAR Export http://www.pastie.org/2180751 (viewable in
http://www.softwareishard.com/har/viewer/)

The 3 POSTS is weird, they all return 200 OK but nothing happens and
after clicking "Use featured image" it shows "Saving..." indefinitely.

All comments/help appreciated,
@msacks