I do not know where the problem stems from a moment before, but I'm glad they found the solution is:)
I wrote a message on the official Activison Support profile, and here it is:
Tomek Borówko - Hi, I have the a problem playing... | Facebook
Feel free to write your comments there - the more information and the biggest chance to resolve the problem :]
Im nnot having this problem (fps drops) in big situations or any specific map, its totally random!
I am experiencing this in every match and every map lately. Now it is occurring on the very start of the match. I generally have taken to the old PC resolution by making my character look up at the sky for a sec to resolve the frame drop on starting the map. It is definitely not a router/connection issue. My opinion on this issue is it will never get resolved or publicly addressed. This will go the way of the "Sound Glitch" in BO2, it will be talked about by everyone, but never resolved.
I contacted Activision support via twitter and have come to a possible fix.
I run at a slow internet speed and the latest big update may have been corrupted due to the slow download (loosing info). Uninstalling and re-installing ghost may fix this. I am getting better internet soon and I will keep all of you posted.
Their answer of redownloading is a run-around answer. Gets you off their back and off to the next support technician when you will most likely find nothing changed. Everyone on here did not get a "corrupted" download....