Apple's iMac MXM Updater to cure iMac's Boot Camp woes

Exclusive: Apple is secretly testing an update for its white 24-inch iMacs that should solve a year-long problem which has prevented many users from running Boot Camp on their systems, AppleInsider has learned.

The company's external and internal testers are validating a small but crucial patch that would improve the computer's handling of graphics cards that use NVIDIA's MXM slot format, which Apple used only for the GeForce 7300 GT and GeForce 7600 GT cards in the now discontinued 24-inch system.

New aluminum iMacs, which use AMD's ATI Radeon HD series graphics hardware and thus a different physical interface, are not affected by the issue.

Almost since the iMac's launch in September of last year, users in Apple's support discussions (1, 2) have reported intermittent success in booting into the Windows-oriented partition after installing Boot Camp. While some systems have worked properly from the outset, many others would boot into a blank screen, always forcing the user to restart back into Mac OS X.

Logic board replacements have often resolved the problem for affected machines but have never been surefire remedies, according to people familiar with the matter. Users themselves have often reported difficulties persuading Apple that the flaw was inherent and covered under warranty, rather than a glitch within Boot Camp itself. And since the multi-OS Boot Camp utility was (and still is) considered a beta when run under Mac OS X Tiger, it receives no official technical support from Apple. This compounded the matter for users.

Though the root cause of the Boot Camp issue has not been revealed, the existence of the patch confirms that the system failures can be controlled through software alone and will avoid costly repairs for the white iMacs, some of which are now beyond their free AppleCare warranty periods.

When Apple would complete its testing of the software update was uncertain. Labeled as "iMac MXM Updater 1.0," the fix is in the later stages of development and will depend largely on the success of testers in isolating remaining bugs. With Mac OS X Leopard expected to launch in late October, the Cupertino-based firm will have comparatively strained resources and a second operating system to test with the updated code.