Dani,
Thanks for the kudos, we love to hear it, and an extra thanks for subscribing.. it's what helps us to keep doing it!
Regarding your issue, can you check that you have the latest version of the Kunena profile plugin? You should see this on the JFBConnect Overview page (if you're using v3.1 of JFBConnect). This issue, we think, was fixed with the 3.1.1 version of the Kunena plugin. If you're using that version, can you check the folder below to see if there's files with your User ID in them? So, if your Joomla user ID is 123, you would see files like 123.jpg.
/media/kunena/avatars/resized
and
/media/kunena/avatars/users
The users directory will have the 'original' file that we import from Facebook. Please see if it's the correct (most up-to-date) version and the resized should be smaller versions of this file. Let us know if it seems like the original and resized versions are correct, and we'll do what we can do to help narrow down the issue.
Thanks,
Alex