Reza/Cam,
First off, I added the subscription to Reza's account, so you won't have to deal with pesky questions going forward.
Second, I looked at the links you sent, and the picture that's been imported is as large as Facebook will send. If you want to stretch it from there, we can likely help you do it through CB, but just want to warn you that the resulting picture will be 'stretched' and possibly become blurry because of it. The picture that we're grabbing from Facebook is below, which you'll see is the same dimensions of what you see in CB:
graph.facebook.com/518546968/picture&type=large
Something you may want to try is saving that picture to your computer and updating your CB profile with it to see what happens. If it doesn't stretch automatically, then we're doing what CB would do normally, and what non-Facebook users on your site would deal with as well.. so fixing it just for Facebook (if we can easily) may not solve all your site problems.
Finally, for the Kunena profile, that's using your CB thumbnail, which is generated when a user's avatar is imported from Facebook. Simply changing the max thumbnail size in the Images tab (in CB Configuration) or the Avatar field (in the CB Field Manager) to a larger size should fix that issue.
Hope that all makes sense. If not, let me know... if you still want help stretching the CB image, I do think we can help though, but would need to look into it more.
Alex