Read about these issues a few weeks ago, out of passing interest really, but have had the same issues myself recently.
I can reply to posts OK but have been trying for more than a week to upload a new Headlines article which included a lot of images - error messages constantly. Martin had been trying to resolve the problem but as yet no luck.
Just to eliminate source issues I even rephotographed the subject, resized everything in Picasa, and still had error messages upon upload. This happened last year as well when I posted a lot of images from the Telford show. I think after it was resolved we decided that the server had problems resizing original image uploads and the pathway locked up.
It's definitely something linked to my account pathway and the iM server, as I uploaded the images without any problem on our club's Facebook page a week ago.
I will say that none of these issues arose before the core upgrade, but it could be that the enhanced capability goes hand-in-hand with an increased tech sensitivity to certain functions that are just outside certain parameters.
So, I'm locked out.