Well if you read the remainder of this post you will find that it wasn't the web shield at all, as the web shield doesn't scan all of those sessionstoreXXX.js files but the file system shield.
So in this case it has nothing to do with the web shield (but the 2500 plus session store files being constantly modified and subsequently scanned), so your experience/problem with the web shield is completely unrelated.
So when it comes to resolving problems with the web shield we would offer suggestions relating to that shield, but what we can't do is make an instant analysis based on the information given. So we have to start gathering information and ensure that there isn't some conflict (most commonly caused by another AV or remnants of one) so we have a clear start point as battling any conflict can make life very difficult.