I am the feeder for the PEI site. I was at work all day when I got home in the evening to check the feed found my computer audio setting had changed somehow from line in to mic audio so reset to the proper setting for line in and all returned to normal. Nice to hear that the PEI site is being listened to. Not sure how that happened but should be back to normal now.
Sometimes it happens when [audio] hardware devices are plugged into the computer. I've caught myself on more than one occasion noticing that Windows XP decided to take my recently plugged in USB webcam as the recording device instead of my pre-selected 'line-in' off my sound card.
A good idea is to check it as often as practical, but more often than not, checking it after you plug-in or un-plug hardware devices will catch most problems and can be quite beneficial.