Some Mac users may have difficulty uploading images.Please check the following setting:
How to Enable Java Applet Plug-in Using Mac OSX10.7 Lion
Step 1:
Click on Go, and then Utilities in Finder.
Step 3:
In the General tab, place a check in the box labeled Enable applet plug-in and Web Start Applications.
For best results, use the "Aurigma" uploader.