actually I thought that too, but then I had her e-mail me the file and it was a 27 kb file. In addition to that we got a response from photopost help desk giving us these recommendations:
That is a PHP/GD2 error which results from gd2 using all the available memory on the PHP system
The workaround I usually post is to increase PHP memory like so or switch to imagemagick which does not use PHP memory
In pp-inc.php you can add ini_set line below the line noted
error_reporting (E_ALL ^ E_NOTICE);
which we changed yesterday and we are still having the problem today. Same user - she is the ONLY person unable to upload.
What else could be causing this?