Can confirm this as well, got into a firefight at Airfield, me and a friend killed total of three guys and my friend died in the proccess. I went to loot three corpses, the moment my friend pressed respawn, his corpse disappeared. The other 3 guys were also despawned, one as I was looting. Can provide video if needed.

Uploaded the .RPT file straight after I lost controls. The throttle disappeared mid flight, the joystick once I was landing.

Uploaded my Dxdiag, short version: using Windows 8.1. The problem seems only to occur with players using Windows 8 and 8.1. Friend of mine I play with use TrackIR 5, Thrustmaster Warthog and pedals without any problems, he is using Windows 7 however.

Happens to me as well, seems to also occur when entering a vehicle (choppers in this case)