We have tried both using slash arguments and not using it, as well as both formats for the URL:
Neither results in the image showing up. Browsing to the URL in the browser just results in the URL showing up in the browser.
If we copy the image out of the moodle data directory and into the moodle directory, we can view it in the browser just fine.
I don't see anything unusual in the logs, an occasional "Undefined index: HTTP_HOST"
We are running 1.8.3 on Debian Etch with PHP 5.2.6 and MySQL 5. GD is installed and enabled.
All our Moodle files are unchanged (according to our source control system), so we are thinking this is a database or environmental change, but as far as we no nothing has been installed or updated.
Can anyone provide any help on how we might debug this issue?