Just wondering if anyone has experienced issues with their MBA fully locking up. This started happening regularly to me (I'm on 10.9.3) and I've never had this issue with the hundred or so Mac's I've owned and worked-on for clients over the last 15-20 years. There is no indication it's going to lock-up ahead of time, but once it does, there's nothing that can be done other than a hard power reset. I've wondered if it's overheating, although the fans aren't kicking on, and it's not related to the common sleep/wake issue because it only happens when I'm in the middle of using the computer (never when it's been sitting unattended). I'll be moving the cursor or typing and for no reason, everything is frozen and unresponsive; no amount of time "letting it sit" makes a difference either. The only similarity I can think of is that a few of the times I know I was in the middle of using Numbers (3.2). Anyhow, I wondered if anyone had similar issues, or knew what to look for if it is in fact overheating. Thanks!