Those who visited AT&T's Web site Wednesday to preorder the device were greeted with the stark message: "Preorders for iPhone temporarily suspended."
"Given this unprecedented demand and our current expectations for our iPhone 4 inventory levels when the device is available June 24, we're suspending preordering today in order to fulfill the orders we've already received," AT&T said. "We are working hard to bring iPhone 4 to as many of our customers as soon as possible."
AT&T said that iPhone 4 preorder sales Tuesday were 10 times higher than the first day of preordering for the iPhone 3GS last summer. The company said its website received 13 million hits Tuesdays from customers checking their eligibility for a phone upgrade.
Preorders are still available through Apple at its store locations, on its website and through its Apple Store App -- though the phones are now not available for shipping until July 2.
Dallas resident and Apple Inc. shareholder Don Bell tried had no luck on the Apple website, so he rolled the dice at the store.
"I want to be one of the first people," he said. "I don't want to wait until August to have this phone."
But it was a no-go for Bell, whose license plate says "GO AAPL."
AT&T said late Tuesday that it was looking into problems that resulted in "customers inadvertently seeing the wrong account information during the iPhone 4 purchasing process," after reports by some who were placing orders that they were seeing the data of other AT&T customers. In some cases, AT&T's systems took customer data without completing the orders.
"We have been unable to replicate the issue, but the information displayed did not include call-detail records, Social Security numbers or credit card information," AT&T said.
Last week, AT&T apologized for a security breach that allowed hackers to obtain 114,000 e-mail addresses of iPad 3G users.
MSNBC's Suzanne Choney and NBC DFW's Julie Tam contributed to this report.
Get the latest news direct to your phone with NBC DFW SMS alerts. Text "DFWBreaking" to 622339 (NBCDFW) to subscribe to this free service. (Message and data rates may apply through your mobile carrier).