Recently we had problem with Facebook SDK, that on IE it remain in redirect loop and hence our facebook application was not working. I test it to find that it wasn’t getting the session detail on form submission. The reason is Security policy of IE that prevent 3rd Party Cookie drop which is required for SDK to work.

Finally got it working by throwing following header:

header(‘P3P:CP=”IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT”‘);

For now I just copy paste it from some site, but be careful all those words has different meaning and you may not want to throw all those words. Hope that help.

This same applies not just to facebook SDK, but anyone using a iframe application with cookie support.