Apple has published an extremely brief technical support document for MacBook Pro owners who are experiencing a whining noise under the keyboard of their machines.

A plethora of complaints have emerged regarding the issue.

If your MacBook Pro is affected, Apple's brief advice follows: "If your 15-inch MacBook Pro emits a high-pitched buzzing sound, please contact AppleCare for service."

The Daily Tech website claims that Apple has said this support will be made available for any MacBook Pro for one full year from the purchase date.

Apple's laptop sales shot for the stars in its last quarter, as the move to higher-speed Intel processors drove demand. Apple laptop sales climbed 61 per cent year on year, in units and revenues.

Apple chief financial officer Peter Oppenheimer revealed that MacBooks and MacBook Pros had increased Apple's US market share from 6 per cent to 12 per cent.

There may be more problems ahead: some MacBooks may also be flawed. There are reports that when the MagSafe power adaptor is suddenly separated from the computer, the computer instantly enters sleep.

What's annoying some customers is that when the computer goes to sleep in this situation, it cannot be woken up again, and the machine needs to be restarted.

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