Full Image path are:

Yes, you can see the domain part is duplicated, right? That's what I'm trying to tell you. Please go to your vBulletin options page and remove the full path. They are not needed to display in your forums. But in order to display correctly in Facebook, I need to use the full path so... your domain will be put in place automatically and if you use the full path in options, it will result into duplication ;)

ok, please guide me to that vBulletin options page / location.

You can change it in AdminCP > Post Icons > Post Icon Manager. Edit each icon please (ew, it's hard if you have many of them). Good luck :D

hmmm, I think I have correct path, see attachment.

Well, this is definitely strange. Check the star.png and the thumb_up.png please. Hmm... I think I will apply a smart rule here to deal with all those urls :D

Yes, all images are in icon folder, I checked again, may be there is a custom skin issue, but I already uploaded all icons to the custom skin folder too.

Update: it was a custom style issue and I correct this by uploading all icons into the custon skin folder, icons are displaying after I run YAFB Hourly Job via Scheduled Task Manager.

but there is another issue:
I think favicon.ico is come because of a thread without having a post icon.

Noticed that in the new 2.o feature the ability to NOT INCLUDE certain forums has not been included as this is very important and in my opinion a HUGE security issue with the bridge. Members and mods should not be able to use this feature on hidden forums to s disclude forums feature should be included in this plugin

With forums which can be viewed by guests, the option are automatically turned off. But if the user decide to turn it on... Hmm, I'm still think about this, should the checkbox be disabled in those situations?

The issue is this.. If my mods are posting in mod only forums and accidently check the post facebook which they are in MOD viewable forums then we have a security breach. We need to have this mod exclude certain forums from even showing any facebook features to prevent any posts back to facebook