"That's a crock," he said, according to Engadget.com." If anyone had said this thing has problems, we would have dispatched people to deal with that issue."
Nevertheless, Jobs admitted that the iPhone 4 drops slightly more calls than the previous version.
The conference comes after weeks of negative publicity, which Apple until now only addressed with formal statements. When complaints surfaced initially, the company released a statement saying that "gripping any phone will result in some attenuation of its antenna performance, depending on the placement of the antennas."
The company later released another statement, repeating its claim that gripping any phone in certain ways could reduce reception. Apple also said there was a problem with the bars that display signal strength and said it would release a free software update soon to fix the problem.
"Upon investigation, we were stunned to find that the formula we use to calculate how many bars of signal strength to display is totally wrong," the company said. "Our formula, in many instances, mistakenly displays 2 more bars than it should for a given signal strength."
At today's conference, Jobs admitted that Apple had "screwed up the algorithm" on the signal strength indicator. "We've been working our butts off" to understand the issue, he said.
Apple's statements did little to satisfy customers, and several lawsuits seeking class action status have been filed.
The backlash reached its peak on Monday, when Consumer Reports said it would not recommend the new phone, though it still ranked it among the world's top smartphones. Then, on Wednesday, Bloomberg News reported that a senior antenna engineer at Apple had warned Jobs early on that the iPhone 4's design could lead to dropped calls.
The Apple press conference seemed to go over well with investors.
When the conference started, Apple stock was trading at $249, and it jumped to a high of $254.97 while Jobs was speaking. (The overall stock market, meanwhile, dropped more than two percent.)
Ross Rubin, analyst at NPD group, said Jobs seemed earnest in his effort to make things right in customers' eyes.
"This clearly represents a good faith effort to address the concerns," he said. "It's not a perfect solution, but there may not be a perfect solution, in that there are inherent tradeoffs in handset design."
Others, however, were not convinced.
"I think it was a mistake to compare this problem to other phones' problems," said Rob Enderle, a consultant and president of the Enderle Group. By not apologizing, Jobs has exposed himself to further criticism and possible retaliaton from other phone companies.
"Saying 'I'm a crook, but hey, so is everybody else,' doesn't usually work,'" said Enderle.
ABC's Ned Potter, Bill Weir and Chris Marderosian contributed to this story.