Problem also occurs on my Lenovo IdeaPad Y450 with a fresh 11.04 installation, but like #5 sometimes the error doesn't appear and everything works fine after rebooting a few times.
On AC power without battery, I can boot without problems. In previous OS and kernel versions, no boot problems as well.
It should be noted, though, that my battery itself is considered "broken" by Ubuntu and Win7 and no longer reports accurate charge levels.
Problem also occurs on my Lenovo IdeaPad Y450 with a fresh 11.04 installation, but like #5 sometimes the error doesn't appear and everything works fine after rebooting a few times.
On AC power without battery, I can boot without problems. In previous OS and kernel versions, no boot problems as well.
It should be noted, though, that my battery itself is considered "broken" by Ubuntu and Win7 and no longer reports accurate charge levels.