The first issue, which some are calling "the black screen of death," manifests itself on unibody MacBook Pros during game play. Users report that their screens go black after just a few minutes of gaming, while the system locks up and the audio enters into an infinite loop.
Once the systems lock up, users say they lose control of their cursor and are left with no other option but to restart their Macs through a hard reset. The issue exists under both Windows and Mac OS X, affecting a wide range of titles that include Call of Duty 4, World of Warcraft, Ages of Empire III, Command and Conquer, Oblivion, Company of Heroes, and others.
Some users believe the problem may be a driver or cooling issue, where the MacBook Pro heats up faster than the internal fans can spin up to provide ample cooling, which then leads to a crash. A few of these users have had some luck mitigating the problem by installing alternative drivers for the notebook's NVIDIA graphics card and using a free software tool called SMCFancontrol, which lets you tweak your fans to maintain a certain speed.
Not all users have had the same success, however. Others report the only surefire solution was to have their MacBook Pro's logic board replaced or have their system swapped out for one manufactured more recently. In these cases, the problems disappear completely, leading some to believe there is a hardware-related issue with an early batch of the notebooks.
For its part, Apple is reportedly acknowledging that an issue exists but has not yet identified the cause.
"Just spoke to AppleCare UK and they also confirm 'Apple are [sic] aware of the issue and are investigating,'" said an Apple Support forum member by the name of omv. He reported that the company is still trying to determine whether the root of the problem lies in hardware or software.
Separately, owners of both the new unibody MacBooks and MacBook Pros are reporting wave-like video distortions while scrolling in web browsers of viewing HD content. They say the problem is common on most systems on display at Apple retail stores, but note the distortions do not appear while running Windows, which may suggest a Mac-specific NVIDIA driver issue.
Adding to that theory, other users note the problem also exists on NVIDIA-based iMacs, but does not show up on the MacBook Air with integrated Intel graphics or iMacs with ATI graphics cards. Another theory is that a combination of the NVIDIA graphics card drivers and Apple's Webkit rendering engine is to blame, which would explain why the distortions do not appear under Windows or Mac browsers that do not rely on WebKit, such as Opera.
Again, Apple is said to be aware of the issue, but in this case is already working on a software fix, according to Apple Support forum member rnicolson:
After discovering this problem on the MacBook Pro I purchased a few weeks ago, I visited the Apple Store in Regent Street to check whether the problem was common to all the new MacBook Pro's. I checked five MacBook Pro's they had on display and they all had exactly the same wave distortion on the screen, when scrolling in Safari using the side bar. There was no distortion when the up/down keys were used. I showed this screen distortion to an Apple salesperson, who seemed genuinely surprised. He disappeared to the back office in the store for a discussion with a 'senior Apple Engineer' and after five minutes he returned with the statement that this was a known problem and there will be a software fix for it sometime...