Sorry, it was a caching issue. I feel a fool!
 
However, the problem with a perfectly legit jpg file being rejected stands. I've seen some reference to it on drupal.org too.
----- Original Message -----
From: Neil: esl-lounge.com
To: support@drupal.org
Sent: Saturday, May 26, 2007 10:46 PM
Subject: Impossible to delete user picture

I am having an odd problem with user pictures.
 
I uploaded one, let's call it Picture A.
 
I then deleted it and my user pic disappeared. As expected.
 
I then tried to upload another jpg image and got the message "the uploaded image was not an image". So then I tried another and Picture A appeared again.
 
So I went to files/pictures and manually deleted it and ran through the previous two stages again with exactly the same results. One jpg got rejected as not being an image and magically, Picture A reappeared again.
 
I am using simply Upload module and have never seen such malfunctioning with core modules. Has anyone seen anything similar before?
 
Neil