I've been having the same problem... I have two or three bars during the match, but it's like my hits aren't even registering. If I'm lucky I can take someone else down, but otherwise it seems like everyone can hit me, but I can't hit them. I hope they fix the problem soon.

Same here. Today I had the drop on a player, shooting him in the back after unloading most of the clip from the scar into his back he turned around and dropped me in 3 to 4 shots. I'm starting to get really pissed off. I'm thinking of deleting everything and starting over and coming back when everything is fixed. My current K/D is .39 and I've never had a K/D that low. Looks like I'm back on Homefront for now.