I keep getting a random error message quickly pop up on the screen of my 2011 13 inch i7 Air. It's one of those standard gray boxes with the yellow caution sign on the right. It's never there long enough for me to catch what it's saying. It can happen anytime, but most recently it occurred while using Facebook. I have the following programs running in the background all the time - Twitter, LogMeIn, and iStat Pro. Any thoughts on what this might be? Hardware Test reports no errors.