Alright, I'm on a 2.4 GHz MacBook Pro, just updated to version 10.5.5. Today, it seems some strange sound output issue has cropped up. Using either the laptop's built-in speakers, or the headphone jack connected to an external pair of creatures, the sound turns on and off intermittently. When I go to System Preferences -> Sound, and select output, the "Choose a device for sound output", I have: Name: External Speakers, Type: Built-in Output. Then occasionally switches to something else, a little too fast to read. Looks like "Something Output (ispk)". Every time the sound goes out, the Balance goes to "The selected device has no output controls". Weirdly, right now, I've got nothing plugged in, and its switching between Headphones, Internal Speakers, and Built-In whatever. Basically, it looks like the sound output stuff is wigging out. Sound works fine through a USB headset. Any idea what the hell is going on?