The issue, according to Microsoft, concerns the asynchronous scheduler component - a part of the USB 2.0 driver that determines when devices can access local memory. With the revision to that driver implemented in Windows XP Service Pack 2, the scheduler can inadvertently be left running. As a result, Windows' internal task scheduler (a separate item) treats the asynchronous scheduler as a running process involving the attached device, and thus stops itself from ever giving the processor the signal to power down, or power lower - to slip into one of its ACPI sleep states. Because the scheduler is running, Windows thinks the system is continually busy. As a result, the computer can use more battery power.

While Microsoft's Knowledge Base article is conclusive and states that the current ACPI driver is a "known problem," we are still scratching our heads why only our Core Duo/945-based platform provoked the error and not the Sonoma or the AMD/ATI Radeon platforms

According to Myers, Intel has asked Microsoft "to fix the registry to make the problem go away." In the meantime, he said, Intel is working to fix the issue by itself: "We are doing additional work on our end to see if there is anything we can do to overcome the same challenge Microsoft is having," Myers said.

If the patch can be as simple as a modification to the registry, the question arises why Microsoft hasn't issued a registry patch. We were not able to reach Microsoft representatives to answer this question and Myers said that he was unsure why the problem has not been fixed so far. "Battery life of Napa is a big deal for us. Microsoft said it is investigating and looking into this issue."