About every 72 hours or so, the sound stops working (through the 27"ACD speakers) and I have to unplug all three connectors and plug them back in to get the sound to work (Late '08 MBP always in clamshell mode hooked up to new 27" ACD). The sound will be working fine, and then out of nowhere I'll hit the sound up or down buttons and there's like 2-3 seconds latency (sometimes up to five) for the volume bar to respond on the screen. No sound. I can't do anything to fix it thus far. I just have to unplug all of the cables and reconnect them (to the MBP from the monitor). That in turn powers off the external hard disk drives I have hooked up to the USB ports on the monitor, which is a big pain. Is this a known issue that I might have missed in a search? Something on my part I'm doing wrong? Any ideas or help would be appreciated.