monocolumn, thanks for report. I would be interested more in an exact request (URL) it is doing. You can use for that eg. Fiddler (for http sniffing) if you can't do that with your software (but I guess you can do it there too).
Anyway, right now I can expect you are on stable version of Miranda and there were reports that plugin doesn't receive any messages, which means the channel requests are broken. And probably that's even your problem.
So, this can happen when Facebook changes something and for channel requests responds immediatelly with error - that results in Miranda requesting again and again and again - as you can see from your video.
TL;DR: Wait for update of Facebook plugin in stable Miranda NG (shall be here during today or tomorrow) or switch to development version of Miranda NG (which is fixed there for many weeks already).
omniwolf, next time, to help yourself and others, please report such issues!
This always makes me sad when user with some problem just stop using something (and some also start empty complains), instead of letting developer know and fixing the issue...