Having same problem. Seems that "proxy scripts", something new in natty release that might have caused it. Here's entries in my /etc/grub.d
00_header 05_debian_theme 05_debian_theme.dpkg-old 10_linux 10_linux_proxy 20_linux_xen 20_memtest86+ 30_os-prober 30_os-prober_proxy 40_custom 41_custom bin proxifiedScripts README If I disabled the *proxy* files and execute update-grub, no duplicate entries generated Those scripts were created during natty upgrade process, think the upgrade process should have disabled/removed 30_os-prober before adding new 30_os-prober_proxy -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/758887 Title: Following kernel upgrade to 2.6.38-8.42, grub2 generates duplicate entries in the menu -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs