Jobs tried three times during his keynote to do a side-by-side comparison of the iPhone 4's screen resolution versus its predecessor's. He was trying to call up The New York Times' Web page, but it wouldn't load because too many devices in the room were operating over Wi-Fi, swamping the frequency.
Jobs switched to backup phones for the demonstration, but he was still stymied.
"Well jeez, I don't like this," Jobs groused. He abandoned the demo while staffers investigated.
Technological glitches at technology conferences are common, but less so at Apple's carefully choreographed events. Last month at a demonstration of Google Inc.'s Internet television technology, Google representatives had trouble showing how easy it was supposed to be to switch back and forth between browsing Web content and TV programming.
Google pleaded with attendees to shut off their wireless connections, as did Jobs on Monday. He asked bloggers and other people in the room to turn off their wireless connections and put their computers on the floor.
"I think bloggers have a right to blog, but if we want to see the demos we're going to have to do it," he said.
The demos immediately after that went smoothly. But a later demo of a video-calling feature that requires a wireless Internet connection was sluggish at times.