Phoronix has identified the Linux power regression problems it previously noted in Linux 2.6.38 as being related to Active-State Power Management (ASPM) code for PCI Express -- and has published a workaround. The problem, which can result in low battery life with Ubuntu 11.04 and Fedora 15, have been confirmed by Tom's Hardware Guide.

LinuxDevices

 

In this article they discuss how the discovery was made and also publish the fix, which is simply adding an additional line to your boot command line.