comment is not viewable by other

Kavin,
Can you post the URL of the page this is happening on? Each comment box uses a URL parameter to identify comments that are associated with that box. The only reason that I think of is that there are 2 different URLs each user is looking at. Even slight differences in the URL would cause each user to not see the others.

Hope that helps get things started, but if we see the page, we'll be able to post some comments from different user's and see what's happening. Of course this may be related to the UTF URL's, similar to the comment email issue that we're looking into as well.

Thanks,
Alex

Kavin,
The issue you're having is likely due to the Open Graph configuration of your site. It looks like, in addition to JFBConnect, you're using something else to manage Open Graph tags on your page. These are causing conflicts and confusing Facebook.

Here's a few issues I'm seeing. Basically, if you open your HTML and search for "og:", you'll see all of your Open Graph tags. These issues should be cleaned up:
1) The "type" property has extra quotes in it. If you're using defaults box or the JFBCGraph tag to include this, you shouldn't wrap the value in quotes.
2) The first "image" property has extra quotes too. Same tip as above.
3) There are 2 URL properties. The first one looks to be from JFBConnect and is the URL of the page. The other looks to be generated by something that works with Virtuemart. Either should work, but you can't have both. Facebook associates Comments and Likes to the URL specified here, and is likely where your main issue is coming from.
4) There are duplicate title and description tags

Hope that helps get you started. If you have an open graph generator specifically for VirtueMart, that may likely work better than our generic site-wide one. So, the best course may be to disable Open Graph integration in JFBConnect.

Thanks,
Alex