I've had this problem both in 2.3 and 2.2.1
I try to upload an image and it seems successful, but doesn't give me an option to show full size or thumbnail, it only has the options of linking to "file" or "none".
When I send it to the editor, it just sends the filename.
When I "browse all" images, I just get grey boxes with filenames on them.
This is happening on two different versions of WP on two different servers. What's happening?