Apple is working on a software update to address hard drive issues affecting its latest 15-inch and 17-inch MacBook Pro laptops. Users are complaining in droves on Internet forums that machines configured with faster, 7,200-rpm Seagate hard disk drives (HDD) make clicking and beeping noises that are often a precursor to slowdowns and freeze-ups.

An Apple spokeswoman could not elaborate about what fix the company is working on or when it might be available, but said Apple is aware of recent complaints.

Comments on Apple support forums, which have grown to more than 80 pages in length, indicate that the drive problems are related to the anti-drop sensor in the Seagate Momentus 7200.4 HDD (model ST9500420ASG). Even though the issue may be related to the motion sensor, the problem occurs whether the computer is being moved or is stationary, users said.

One user from Southern California, "wessto," posted comments on an Apple discussion forum describing the problem: "I recently purchased a new MBP [MacBook Pro] 15, 3GHz, 500 GB 7200 rpm hard drive, build-to-order. The hard drive appears to be a Seagate ST9500420ASG. I am experiencing a strange hard drive click followed 80% of the time by a beep. It is definitely not a beep from the speaker. Additionally, it happens at any time, even when the computer is sitting on a perfectly still table."

Upset MacBook Pro owners also weighed in on forums at AppleInsider.

On the AppleInsider site, a user named "mgoldman" said: "I bought a 3.06GHz, 4GB RAM, 500GB 7200RPM MPB the week they were announced. For the first week after I got it, it was normal, except for the weird electronic beeping coming from the HD. At first, I thought it was just a new HD technology that occasionally made noise. Then, performance got progressively worse. I usually give this machine a workout -- running VMWare virtual machine with a host of other apps on the Mac side. It started to get sluggish after about 2-3 days. The hard drive would seem to hang up.... Then..., 2 weeks into owning the machine, a cold start first thing in the morning took 10 minutes. After it booted, any click on an icon rendered the MBP useless -- beach ball and unresponsive. Sometimes, after about a minute, the machine will carry out the task you clicked to do, but then immediately go back to being unresponsive."

AppleInsider said users appeared to solve the problem by replacing the beeping/clicking Momentus 7200.4 drive with a more recent models. "But this hasn't been broadly confirmed as of this writing," the site reported.

Among those who have also seen the problem is a Computerworld editor who in July bought a 15-in MacBook Pro with the 7,200-rpm drive. A few days later, he began hearing a series of clicks. The noise went away for a few days, then returned -- this time with an intermittent beeping. Following the advice on Apple's forum from other users, the editor turned off unnecessary services running in the background, to no avail. "It's just the beeps I hear and sometimes it's click-click-beep. The click sounds like a [drive] head parking. The beep sounds like an error message."

Today, the editor experienced a drive pause that lasted about 15 seconds. When the computer was again usable, multiple windows he had been trying to open popped up all at once.

This is also not the first time this year Seagate has had problems with its 7,200-rpm hard drives. In January, Seagate's support forums were flooded with complaints over drives freezing up during data transfers -- or failing all together. The company said that problem was caused by a firmware bug affecting not only the 7200.11 model but several other models manufactured through December 2008, including the DiamondMax 22, the Barracuda ES.2 SATA and the SV35. Seagate issued a firmware upgrade. Several MacBook Pro users have posted videos to YouTube demonstrating the beeping and clicking noises associated with the drives. Some even added a dash of humor by mixing the sounds in with a MacBook Pro commercial.