.PHP format
Matt,
You've used .PHP format (AOL ART) for your Avatar. Some people's browsers (mine included) do not have support for .PHP format without downloading the appropriate "extensions". .PHP is not really a common format. Depending on your browser "settings" it may/may not pop up a window asking to "dowload support for AOL ART" format. If this happens, then click yes. It's only 165K. (bout 10 secs), then you should see the Avatar.