Make sure you have the right permissions on the direcory and on the images....
If you web server is running under user "username"
(you should be root to do the following)
chown username:username <file or directory>
obviously replace <file or directory> with the actual file or directory name...
If that doesn't do it then try the following
( you should be the user that the web server is running under
when you do the following...root is ok too)
chmod +r <file or directory>
or
chmod 700 <file or directory>
Basically the web server needs access to files before it can serve them.
