A number of iPhone owners in the UK are complaining of a weak signal or no signal from O2's network. About three dozen people have reported problems with reception, mostly when they are indoors, in threads at Apple's discussion board. Some said they received a good signal when using different phones, also on O2's network, in the same location.

"My iPhone can barely pick up even the slightest signal, although on occasion can pick up 3 bars, only for it to drop out again. I have two other O2 phones, a Sony Ericsson and a Nokia N95, with no reception problems at all," wrote a person using the name lawlbaker2.

See also:

Apple iPhone review Nokia N95 review

A few people said the problem clears up when they put their phones in the charger cradles, even if the chargers aren't plugged in. That led to speculation that the antennae in their iPhones are weak or faulty, and that the signals get a boost when touching metal components in the cradles.

"I am also having the same reception problem whenever I am in a house; outside is generally fine, as is also when the phone is in its cradle," wrote a person using the name jia10. "It does therefore seem as if the problem is a hardware one (such as the inbuilt antenna at the base of the phone), rather than a software bug that could be fixed with an update."

Lawlbaker2 posted photos of his phone on the web to illustrate the problem. A few said they exchanged their iPhones and that the replacements worked fine, although for some they did not.

It was difficult to gauge the extent of the problem. More than 5,000 people have viewed the threads on Apple's board. Along with the complaints, about 10 people wrote that their phones were working perfectly. A few users started a much smaller, similar thread at O2's website.

Apple representatives in the UK did not return calls for comment on Monday. A spokeswoman for O2 said there are "no problems whatsoever" with the O2 network. She said O2 is "aware" of the discussion thread at Apple's board, but she would not say if O2 considers it a problem or whether it is investigating.

There were no significant complaints about other connectivity on the device, such as Wi-Fi or Bluetooth. At least one user said cellular reception was better with the Wi-Fi turned off. Another fixed the connectivity problem by restarting his iPhone.

"Most of the time it's okay but last night I tried to make a call and noticed the iPhone had no signal, but my other O2 phone had full strength. I switched the iPhone off (or on to standby, with the button on top) then back on again and the signal came back up to full," wrote the user, who signed his post Paul Willis.

Reviews of the iPhone have been mostly favourable, and O2 said it sold "tens of thousands" in the UK over the weekend it went on sale. There have been a few launch glitches for Apple, however: in the US, some people had to wait a few days to activate their iPhones because AT&T's system was overwhelmed. And Apple's partner in Germany, T-Mobile, has been forced to sell an unlocked iPhone alongside the one tied to its network, because of a challenge from Vodafone over European competition laws.

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