Were you among the lucky few who were able to pre-order an iPhone 4 on Tuesday? Consider yourself lucky; Apple fans who pre-order their phones in the days ahead could now be waiting until July 2 to receive the device.

Were you among the lucky few who were able to pre-order an iPhone 4 on Tuesday? Consider yourself lucky; Apple fans who pre-order their phones in the days ahead could now be waiting until July 2 to receive the device.

The AT&T Web site, meanwhile, currently says that "Pre-orders for iPhone [are] temporarily suspended."

The Apple and AT&T Web sites , resulting in timed-out browsers and 404 errors. By day's end, Apple's Web site had switched the expected ship date for the device from June 24 to July 2.

"IPhone 4 pre-order sales yesterday were 10-times higher than the first day of pre-ordering for the iPhone 3G S last year. Given this unprecedented demand and our current expectations for our iPhone 4 inventory levels when the device is available June 24, we're suspending pre-ordering today in order to fulfill the orders we've already received," AT&T said in a Wednesday statement.

"The availability of additional inventory will determine if we can resume taking pre-orders," the company continued. "In addition to unprecedented pre-order sales, yesterday there were more than 13 million visits to AT&T's website where customers can check to see if they are eligible to upgrade to a new phone; that number is about 3-times higher than the previous record for eligibility upgrade checks in one day."

"We are working hard to bring iPhone 4 to as many of our customers as soon as possible," AT&T concluded.

Radio Shack, which was accepting in-person pre-orders at its stores, also suspended the program due to demand. "Requests have ended due to overwhelming customer response. More launch details to come," the company wrote on its Twitter feed.

Best Buy was also accepting in-store pre-orders, and by late Tuesday evening, a Best Buy representative tweeted that the program was still on. She also said that Best Buy would be scheduling appointments for pick-up and activation on June 24, so buyers do not have to wait for hours in line.

"As of this morning, we are still taking pre-orders on the device in our stores. As you might expect, there has been a ton of customer demand and, based on what we have heard from customers, their experience in pre-ordering the iPhone 4 at Best Buy has been a good one," Best Buy said in a Wednesday statement. "As we get further from the start of the pre-sale (which started yesterday), we are upfront with customers telling them that they are on the priority list to get a device and that we are still working through what the inventory will be on the phone come June 24."

A Best Buy FAQ said the store is only accepting pre-orders, however, for the black iPhone 4. "We stopped taking pre-orders for the white iPhone 4 after Apple stopped taking pre-orders" for that version, the store said.

[Editor's Note: Later in the day, Best Buy suspended iPhone 4 pre-orders.]

Best Buy pre-orders placed for the white version are still valid, but buyers might not receive it on June 24. Best Buy also does not guarantee that buyers will get their pre-ordered black phones on launch day.

"Any inventory received will be used to fulfill outstanding pre-orders in the order they were placed," the store said. "For example, if the store has twenty pre-orders on launch day but only received fifteen phones from Apple, then the first fifteen pre-orders should receive their phone on launch day."

Wal-Mart is also offering the iPhone 4, but was not accepting pre-orders; only in-store purchases beginning June 24.

Error messages and overwhelmed systems were reportedly not the only problem users encountered on Tuesday. In the wake of that accidentally exposed the e-mail addresses of , Gizmodo reported that several of its readers were shown AT&T order screens from other users when they were trying to pre-order their iPhone 4.

"We have received reports of customers inadvertently seeing the wrong account information during the iPhone 4 purchasing process. 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. "In the meantime, we are looking into this matter."

The iPad e-mail glitch came to light after Goatse Security alerted Gawker to the problem. In related news, CNet reports that Andrew Auernheimer, who is part of the Goatse Security team, was arrested in Arkansas on Tuesday on drug charges, prompting some to speculate that it was related to the AT&T hack.

Editor's Note: This story was updated at 12:15pm Eastern time with comment from AT&T and Best Buy.

UPDATE: Later in the day, Apple apologized for the technical glitches, and said the company sold 600,000 iPhone 4's in the first day. .