I bought my Mac Pro about 5 months ago. For the past 2 months, however, I have been hearing single BEEPs -- not at startup, just during idle time when my Mac Pro is sitting there like normal. It happens sometimes once a week, other times every few days. This is odd, because it's not like the normal "alert beeps" that occur at startup, alerting of a RAM seating problem, etc. The beep noise itself is one beep -- it sounds like an actual (intended) beep by it's frequency, almost like an older computer (circa 1990s) when you start it up. I've heard some of the hard drive beeping videos on youtube, but many of those are not very fluid beeps -- more like high frequencies caused by spinning discs. This is a real beep. One theory I have is that it isn't my Mac Pro, but my PS3, Xbox360, Apogee Duet, or a running watch that sits near the Mac Pro. But the more and more I think about it, the more I suspect the Mac Pro. Can someone please shine some possible light on this? It's driving me nuts! Plus, if there's something messed up and my MP is trying to alert me, I want to know.