I had trouble uploading a new project logo. At first I was thinking that the upload did not work at all, but I found a lot of bug reports about this issue and finally figured out how to press the save button. Darn.
However, the site's behavior is kind of misleading, because the image shown after uploading a new logo can be understood as "still uploading" or "erroneous image". Further more, I want to see if the new logo looks good, before hitting the save button.
In my opinion, one should see the uploaded logo as preview. Of course, the user has to be informed, that the shown image is just a preview and he has to hit the save button to actually change the logo.