Lorenzo,
Disregard the problem with the 404 error. The first URL you posted above was simply messed up. I fixed the URL in the post, and it works now.
So, we've done a bit more testing, and here's what we've found:
http://www.liveandshop.net/index.php?option=com_content&view=article&id=91&device=iphone
On this page, on the iPad (2), the popup works fine. The source code HTMl look fine, and I really don't see any reason the popup shouldn't work.
http://www.liveandshop.net/index.php?option=com_content&view=article&id=135&device=iphone
This page, again, the iPad2 has no problems. However, looking at that page's source code shows that there are actually some huge HTML problems, and it seems that 2 pages are trying to be rendered. If you look at the code, there are 2 html, head, and body sections. Additionally, the JFBConnect system plugin is inserting the Facebook Javascript library twice, and initializing it both times. Something's very wrong with the structure of this page, and I wouldn't be surprised if that's the reason Facebook is having difficulties.
Our iPod Touch had issues showing the comment box or like button on both pages. That area was simply blank. The iPod Touch we have is the 2nd generation one, which only runs up to iOS 4.2.1. I have no clue why the buttons wouldn't show, since on SourceCoast (and other pages) the Facebook widgets do load. Obviously, the old iOS version could be part of it, but pretty confused as to the cause.
We'll keep you posted on more testing we plan to do this next week. Please investigate the issue on the second page, which may help narrow down the issue on all pages.
Thanks,
Alex