I've been having a bit of a fight with facebook recently. It will not display any thumbnails from wordpress - the only thing that shows up is a blue box with what looks like a standby button on it.
If you try and add this link to a facebook page you will see what i mean http://www.theothersidemag.co.uk/2011/02/video-of-the-week-alessis-ark-wire/
It will not display the corresponding picture. I've tried all realms of fixes... turned off the plugins, added suggested plugins but to no avail. I really hope someone can help me out as this is driving me nuts.