I turned off my automatic update after last year on April 14, when that a Windows update on one of our computers interrupted the functioning of our tax preparation software. (we are a CPA firm). Intuit fixed the problem on the computer, and subsequently let us know that the update was also reported to be interfering with Quickbooks. The timing of the problem, needless to say, caused us a bit of anxiety.
Smart. As an ex IT person(retired)I have never enabled automatic updates. I always make it ask me what I want to install. I recently had problems with SP3 for XP. It works ok on my roll your own computer but causes no end of problems on my Dell. I understand from some other Dell owners that it has caused problems with their machines also. Bottom line: Don't trust updates!