The avatar (profile photos) are not imported

i am working on importing ning to wordpress recently and i found a problem that the importing of avatars are failed in most this kind of plugin.
I found WPMU by search engine, and this plugin is the main reason for me to buy your service, however, I find this plugin still doesn't work.
Here is the link where i set up the service.
http://shift-3.com/scitribes/members/
Is there any technician can help me?
I can provide my member data file if necessary.
I think the problem may be on Ning side. Ning had update some of the features, while this plugin haven't adapted to these updates.

thanks very much.
-Haojian.