Phoronix reports another power issue in Ubuntu has been discovered, you can read it over here.
"Since Friday there's been a number of Phoronix articles about
a very bad power regression in the mainline Linux kernel, which is
widespread, Ubuntu 11.04 is one of the affected distributions, and has
been deemed a bug of high importance. This yet-to-be-resolved issue is
affected Linux 2.6.38 and 2.6.39 kernels and for many desktop and
notebook systems is causing a 10~30% increase in power consumption.
Nevertheless, this is not the only major outstanding power regression in
the mainline tree, there is another dramatic regression now spotted as
well that is yet-to-be-fixed."