I've had a install of 11.10 for a while and decided to upgrade to 12.04. I tried to upgrade in Ubuntu, and all went well until the end when it couldn't install the bootloader for some reason. So I put the 12.04 image on a flash drive and installed. First time it had bootloader issues. I tried a different flash drive and it worked. But, when I booted up the first time, I noticed I had about five duplicate boot menu entries. I had the usual Linux generic, recovery mode, two memtest, and my windows 7 entries, but I also had about five entries labeled "Ubuntu 12.04.1 LTS (12.04) (on /dev/sda5)".
Once I got my Ubuntu all set up, I installed Burg, Grub Customizer, and Ubuntu Tweaks. Tweaks wasn't showing I had any old kernels. I ran update-grub2. I fired up Customizer and unchecked all the duplicates (they appear under the os-prober menu) so that all I had was Windows 7 and one of the Ubuntu 12.04.1 entries. I saved and then ran the Burg emulator to see how it looked. I still had some duplicates, despite unchecking them. I opened customizer again to find that my duplicates were still unchecked, but NEW duplicates had been generated. I kept trying to uncheck the duplicates and save, then refresh the list, and it kept generating new duplicates. If I uncheck all the duplicates and the "new entries" entry under "os-prober" it will stop generating new entries. Also, the "Ubuntu 12.04.1" entries boot the same operating system as the Ubuntu generic entry at the top of the list.
I went from about 5 to 12. I've never experienced something like this before. How do I get rid of my existing duplicates permanently and prevent new ones from being generated without having to uncheck the new entries option under os-prober?