从WEBWIZ直接转换过来的avatar开始不能直接在phpbb3的控制面板里显示，但在帖子里显示是没有问题的。
在IRC上求教后，方才知道需要把avatar都要拷贝到images/avatars/gallery/下的一个子目录里，而不能直接拷贝到gallery目录下面。
<wlx> hi, how to display avatar gallery? It is not shown in my phpbb3 forum.
<wlx> and I have change the images/avatars/gallery to mode 777
<wlx> I can upload avatar from my computer, and that does work.
<karlsemple> Have you enabled the gallery avatar setting in the Admin control panel?
<wlx> yes, I do
<karlsemple> and the gallery images are inside subforums inside the gallery folder?
<wlx> sorry, I don't understand your meaning.
<karlsemple> the images do not just go inside the gallery folder
<karlsemple> they have to be inside subfolders
<wlx> the images are in images/avatars/gallery/ directory
<wlx> so they must inside a sub-directory?
<karlsemple> they need to be in subfolders so for example /gallery/cars/
<karlsemple> the subfolders become the categories in gallery selection part of the UCP
<karlsemple> so inside images/avatars/gallery/ you need other folders which will then contain the images
<wlx> oh, yeah, it does work now! thank you, karlsemple !