The comments plugin requires an application id to properly namespace the provide

hello there,
recently i have installed plugin names “facebook comments for wordpress”. when i installed that programme, it worked like charm….for two days it was awesome, but for some unexpected reason, from today it says :

The comments plugin requires an application id to properly namespace the provided xid.

i uninstalled, then installed again. i checked my application ID, API, secret code, everything seems to be fine. but still i am getting same touuble. to make a live inquiry, please visit http://pcforum.cimax.se/?p=248 in the bottom, you will see facebook kommentarer and beneath, you will see the error. please someone suggest me, if anyone faced the similar problem.