JComments + Kunena: Avatars not showing

[koopa]

JComments (Latest version)
Kunena (1.6.3, latest version)

I follow this instructions:
1) Install and enable the plugin
2) Configure the plugin
3) Enable plugins in JComments settings
4) Enable Gravatar in all usergroups
5) Install and configure the module (latest comments)

But I can't see the avatars (only the default one) in the articles and in the module. BTW, the (default) avatar of registered users links to the user in Kunena.

Any ideas? Thanks.