FB social plugin integration

[color=#282828][font=arial, verdana, tahoma, sans-serif]FB social plugins when integrated to the site, sometimes pick up random thumbnails from among the existing images on the page[/font][/color]

[color=#282828][font=arial, verdana, tahoma, sans-serif]I am trying to integrate a social plugin to the product pages - now when I do that the plugin picks up a random image instead of the product thumbnail[/font][/color]

[color=#282828][font=arial, verdana, tahoma, sans-serif]To fix this problem, FB suggests that I insert the following tag in the section of the page[/font][/color]

[color=#282828][font=arial, verdana, tahoma, sans-serif][/font][/color]

[color=#282828][font=arial, verdana, tahoma, sans-serif]For this to appear on every product page I need to know how the thumbnail url is built by the cart so that I insert in the index.tpl[/font][/color]

[color=#282828][font=arial, verdana, tahoma, sans-serif]Anyone any advice?[/font][/color]

[color=#282828][font=arial, verdana, tahoma, sans-serif]Thanks[/font][/color]