I ran into a variety of problems when adding images to a post today. Its hard to isolate them, so if you'd like some help doing a controlled test, let me know. Here's the jist of what I ran into:
1) Sometimes when I would browse & add an image & then send it to the editor & try to save & continue editing, I would get a "do you really want to leave the page; you may lose your changes" error pop up. If I continued, it did do the save & didn't lose changes.
2)Often when I went into the HTML editor to place images where I wanted them and used an align= tag and then saved & continued editing, the align tag wouldn't save. (Usually, but not always, when I had added alignment to more than one image at a time. I found if I was sure to place the align tag early in the image call, it worked best. My HTML skills aren't perfect, so I often end up putting an "align=" anywhere w/in the image call.)
3) Sometimes when I uploaded a few images & sent them to the editor & "save & continue editing", the images wouldn't save in the editor. (Usually if I'd added more than 3 images).
4) Sometimes when I would browse & upload an image & then try to send it to the editor, I would get an "error on page". And it wouldn't send to the editor. If I then "save & cont. editing", it would sometimes let me then load the image to the editor.
Sorry, not perfect control group bugs, but maybe its a start?