Hi, I switched from Galaxy Note (running Android 2.3.3) to Note 2. When I was using Galaxy Note, I sometimes used Keis from Samsung. When I got the Note 2 and connected it to my Mac (running Mountain Lion) for charging, I often saw a message on my phone that Android File Transfer is required for file transfer between the Mac and the device. I installed Android File Transfer. However, I always get the message on my Mac that the device cannot be connected. Even I rebooted the Note 2 does not help. I also noticed that after installing this program, my Mac hangs for a few seconds sometime. e.g. unable to see the cursor after waiting up from sleep, sluggish performance, etc. Anybody knows how to fix the issues? What is the difference between Keis and Android File Transfer? Is Android File Transfer necessarily for Note 2 running Jelly Bean? Thanks.