More Apple coverage

Apple's new iPhone 4, already criticized for problems with its antenna and screen, also suffers from glitches in its camera system that can undermine the video chat program that is one of the standout features of the new phone.

iPhone 4 owners first started reporting troubles with the device's camera system Wednesday, the day some users who had pre-ordered the gadget received it in the mail. On the discussion boards on Apple's website and in comments on various blogs, users have complained that the phone's camera application locks up soon after launch, leaving them unable to take a picture.

Some users have been able to use the camera after rebooting the phone, although others have reported having the same issue even after multiple resets.

"When I open the camera app, the app opens, but right into a frozen state," reported one user on Apple's discussion boards. "I've power cycled several times with no effect."

An Apple representative said she was unaware of the problem and declined to comment.

It's unclear how many iPhones are affected. But at least in some cases, the problem affects more than just iPhone users' ability to take pictures. A Mercury News attempt with an iPhone 4 test device found that the faulty camera prevented use of FaceTime, the video chat program.

The phone wouldn't send the user's image to people he contacted using FaceTime. Instead of seeing the user's face, the person on the other end of the call saw a blank screen. The problem could not be corrected by rebooting the phone.

Unlike some users who have reported similar problems, the Mercury News iPhone 4 test user was able to take pictures with the phone's rear-facing camera. But if he tried to take a picture with the forward-facing camera, the application would lock up and not allow him to use either camera. The only way he found to unlock the camera program and resume using the rear-facing camera was to turn off and restart the phone.

The camera troubles are the latest problem to come light with the new iPhone. Previously, Apple acknowledged that the gadget's antenna can have a hard time getting a signal from the wireless network if users hold the iPhone in a particular way.

Meanwhile, numerous users have reported seeing yellow discolorations on their iPhone screens.

Those troubles don't seem to be affecting iPhone sales. Apple announced Monday that it sold 1.7 million iPhone 4s in its first three days on the market.

Contact Troy Wolverton at 408-920-5021. Follow him at Twitter.com/troywolv.