Apple's new iPhone 4 smartphone has been hit by an increasing number of problems according to reports from users of the device, which launched last week.
Problems include yellow discolouration of the phone's Retina Display, irregular behaviour of proximity sensors, reception problems, and now reversed volume control buttons.
Some handsets are said to have been shipped with the volume control button the wrong way around - when users press the '+' button, the volume decreases.
It is not yet known how many of the devices suffer from this issue, but you can click here to see a video of the problem in action.
Apple has consistently defended its smartphone from its critics, stating that the discolouration was only a temporary issue, and suggesting that people learn to hold their phones differently to avoid reception issues.