I don't have that problem but I am having a problem with getting hit by bullets when no one is around me
I remember a couple of times playing MW3. I would be behind cover reloading or capping a flag and all of a sudden up popped the medal for killing someone with a long shot even though I never shot anyone.
I had that happen to me last night. I was using the s12 shotgun I hit this dude like 5 time he killed me then all of a sudden I got a headshot medal lol