Lagging movement detection and keystrokes

[ThaDaLinkWent]

My first thought on this was maybe it has something to do with the host having a poor connection that was causing me to lag uncontrollably. But basically what happens every now and then is I will gently tap forward to walk and my character won't stop moving forward even after take my hand off the key. My character literally would not stop walking forward until I walked him into a wall. It has notihng to do with my system being old and I always keep it clean because on average with this game I can crank out at least 55-60 fps surprisingly. A majority of my time with this game I'm moving smoothly and fluidly across the screen no problem. But when lag hits I can't stop myself from moving and I'm unable to move through doors yet my allies can even though I don't see it open on my screen. It took me 3 minutes just to move through a single door when the lag is really bad. Even when I went on a mission by myself the lag was unbearable which is extremely rare but I'm still not sure what causes this seemingly random lag. Since the last update it's become noticably worse. How common of a problem is this with this game?