For reasons unclear, the online store was not responding Wednesday morning

[UPDATE: As of 11:10 a.m. EST the store seems to be functioning properly. No new products that I can see. Never did get an explanation from Apple PR.]

[UPDATE 2: As of noon EST, the site seems to be misbehaving again. Still no word out of Apple.]

[UPDATE 3: Reader Mehdi Daoudi of Catchpoint Systems reports that the site had fully recovered by 1:40 p.m. Meanwhile, he has quantified the scale of Apple's Wednesday morning problem with some scary looking charts, one of which we've copied below. Still no explanation from Apple PR.]

Click to enlarge. Source: Catchpoint Systems

[UPDATE 4: MacRumors notes that Apple has added a social dimension to its online store -- allowing users who are so inclined to alert their Twitter and Facebook followers that they have purchased, say, an iPod or a Mac Pro. It's not clear how this could be related to the Wednesday's outages.]

The Apple Store often goes down in a good way -- with the classic yellow Post-it note that signals the imminent arrival of a new product or service.

It went down Wednesday morning in a bad way, failing to respond to requests from its own Web browser and triggering instead an error message telling would-be visitors that "the server where this page is located isn't responding."

Trouble at the North Carolina server farm? A denial of service attack by hacker or hackers unknown?

We've asked Apple (AAPL) PR what's going on. Will update if we get an explanation.