I also had this problem with my HP G60-445DX laptop, i then downgraded to grub and immediately the resetting issue disappeared.
Followed the instructions from this site http://icewalkerz.blogspot.com/2010/05/reverting-to-grub-legacy-ubuntu.html -- GRUB boatloader on Samsung NB30 netbook causes reboot https://bugs.launchpad.net/bugs/612010 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs