I have altered the addon_avatar_options file so that only one path is used for the uploads ...
/* Avatar add-on settings */
avatarDir='../intro/shared_files/avatars'; //general path to your directory, where "avatars" directory will be CREATED and used. On Linux/FreeBSD/Unix systems, it must have 0777 privileges. Many miniBB plugins will use this directory, so if you already have one, it is better to keep one directory for all shared files. No slash at the end!
avatarUrl="/intro/shared_files/avatars"; //general WWW path to avatars images. No slash at the end.
The above makes the upload process use the same directory, along with the forums all displaying the same path.
PS: I have left off the $ symbol from avatarDir and avatarUrL as the forum will not allow it.