Intel may be off the hook as the source of a bug observed by reviews that significantly reduces the battery life of Core Duo-based notebooks - apparently it's all Microsoft's fault. Or is it?

The glitch was first noted by Tom's Hardware Guide last week. The site identified a persistent power drain whenever USB 2.0 devices are connected.

A bug in Intel's processor or chipset? Not so, said Intel representatives cited by TG Daily. It's a fault in Windows XP Service Pack 2's Advanced Configuration and Power Interface (ACPI) driver - a problem allegedly documented in Microsoft's Knowledge Base in July 2005, but still unfixed.

But here's the thing. TG Daily tried to replicate the problem with a previous-generation Centrino notebook and failed. If the glitch is indeed a problem with ACPI, it should have appeared in the older machine. That it didn't suggesting the real issue may lie somewhere between ACPI and Intel's 945PM chipset.

Intel told the site it has asked Microsoft to fix the problem, and that it's doing work of its own to nail down a solution. ®