Ning To BuddyPress avatars not importing

Hi,

We have tested the plugin multiple times on a site we migrating from Ning to WordPress - users and profiles are all successfully imported, but none of the avatars are being imported only the standard BP avatar are assigned to the user.

Any ideas as to what the issue might be?

Wordpress 3.0.1
BuddyPress 1.2.6
Importing around 6000 users.