Add Media Glitch on post-new.php Page.

We recently updated to WordPress 3.5. Now when our authors create a new post, the add media overlay is glitchy. It doesn’t display images that have been previously uploaded. Also, when you upload an image, it fails at the end of the upload and displays an error. However, the image does get added to the media gallery. There are obviously work arounds for this but it makes it very difficult for our authors to add images to our posts. Is anyone having this same problem? I’m trying to figure out if this is plugin/theme related, or if it’s just a rare glitch that comes along with the new WordPress. Any help would be greatly appreciated.