I recently upgraded the appearance of this blog - just slightly - by cleaning up the header. What you see above is a graphic. I did this a couple days ago, with no problems.
The following day, I decided to write about my work. So I wrote text, and composed it, and made Customising The Header #2. Then I added some pictures, showing the blog header appearance, as I progressed with the project. Or I should say tried to add pictures.
I could select a picture, and hit the Upload button. And the spinner would run for a few seconds, but nothing would upload. Even clearing cookies, which I tried twice, and verified that I was using a different Blogger server, brought no relief. Nor did uploading to a blank post, tried in both "Edit HTML" and "Compose" modes. Nor using Firefox or Internet Explorer.
Meanwhile, simultaneous improvements to PChuck's Network, which is a Classic blog, proceeded nicely. Pictures were a useful addition to my Network Connections wizards instructions.
So, I guess Beta blog picture uploading is broken. I'm not alone anyway.
(Edit 9/7 17:40): A very interesting forum thread involving Blogger Employee AND Jehovah himself, Pete Hopkins, Google Blogger Help - Publishing Trouble:
Why can't I upload a pix? is a start. Watch this post (or the thread).
(Edit 9/8 17:00): A post in Blogger Beta Known Issues:
Some users are unable to upload images suggests
clearing cache. This seems to work, though not always on the first try.
(Edit 9/13): The procedure of clearing cache appears to be effective against cases where the upload appears to be successful, yet clicking on Done takes you back to a post editor where no code is inserted. Now we seem to have a new symptom - no Done button appears. Clearing cache appears to have a mixed effect here. This problem is still open in Blogger Beta Known Issues:
Some users are unable to upload images, though some links there may be misleading.