Facebook Error 500: POST data is missing in the POST

Starting from mid-May my Facebook application (FOAF) was throwing error message "500 POST data is missing in the POST" while I had no changes in the code for ages. A little bit of googling unveiled an error with Facebook Rest Client CFC:

Line 720:

<cfhttpparam name="#key#" value="#arguments.params[key]#" type="url" />

has to be changed like:

<cfhttpparam name="#key#" value="#arguments.params[key]#" type="formfield" />

So Facebook have changed validation to reject incorrectly posted data.