Image uploader randomly stopped working

Ok, I realise this may be something of a contentious issue around here, but I’m really at a loss as to what has happened. I have been happily updating my blog tonight, adding images to posts. After creating 4 successful posts, the image uploader randomly stopped working. I have not done anything to my server or the wordpress install. I have also not transferred anything to the server.

What is happening seems to be that the image uploads, but then nothing appears in the dialog box. There is no data on the image, or a thumbnail. I also can’t find it anywhere on the webserver. When i insert the “blank” image into the post, it does nothing but close the dialog.

I am using Safari on the mac, and have reset it twice. I have tested transferring files via ftp and other upload forms and that works fine. I have tried different images – files, sizes and types, but none worked. Even images I have already uploaded once tonight. What’s most annoying is that between my last image upload and the first failed one there was a matter of minutes.

Any ideas?