Apple has an exclusive deal with network operator O2 in the U.K. -- but O2's web-based activation system requires the use of Microsoft's Internet Explorer browser to register a new phone: It won't work with the Safari browser bundled in Apple's Mac OS X.
In its Regent Street store, Apple had installed VMware Fusion desktop virtualization software on some of its Macintosh computers, allowing them to run Internet Explorer on Windows, but the activation process was still not working.
"It just goes dead," said would-be customer Mark Phipps, who left the store frustrated and without an iPhone 3G.
The problem, though, was not with the browser: It was in O2's back-end systems, initially overwhelmed by the demand. Customers using PCs at O2's own store on Oxford Street had problems accessing the activation servers too.
An O2 spokeswoman said the company had experienced some "IT hiccups," but everything was working normally by around 10.30 a.m.
Would-be iPhone 3G owners like Phipps, who couldn't hang around for the hiccups to pass, had to leave the Apple store empty-handed.
"They wouldn't reserve us one, which is a real kick in the teeth," he said.
Phipps is one of at least three customers who left the store disappointed by the delays.
Another, Josh Young, said the activation process was completely broken. He planned to return later.
The short line that had formed outside the store by the time it opened at 8 a.m. quickly moved inside, but two hours later the line had lengthened and extended out onto the street again.
Further details were hard to come by: Apple Store staff would not allow journalists inside the building.
At around 10.15 a.m., Nick Davies was among the first customers to emerge from the Apple store with an activated iPhone -- his fourth. His earlier purchases included a U.S. model for which he was unable to activate a U.K. data plan, and an 8G-byte U.K. model that he replaced with the 16G-byte version when the other filled up with data. He said he gave his first-generation iPhones to a friend and family members.
The launch went more smoothly in Japan, where the iPhone went on sale for the first time. The first new iPhone owner emerged from the store of Apple's local partner, Softbank, within 20 minutes of the launch.