os-prober giving wrong UUID for Arch Linux

Up until yesterday, everything was working find and os-prober was successfully generating menu entries for the Arch Linux install. However today when I tried to boot into Arch, I got an error that the root file system could not be found at the UUID it was trying to use. After some tinkering I was able to get Arch to boot by manually changing the root to the actual partition "/dev/sda7" as opposed to using UUID. I was wondering what might cause os-prober to be generating this invalid configuration just for the Arch Linux install. It does fine still for the openSUSE and Windows 7 installs. One other thing to note is that it has added "rw quiet" to the end of the boot line for Arch Linux. That is not something it previously did, and I am wondering if whatever changed that has to do with why the UUID is incorrect. Below I will post the menu entry for Arch Linux. As you can see os-prober has the --set-root= 'some UUID' part with the correct UUID, but later on when booting linux it has -root=UUID='some other incorrect UUID'. Just to clarify, I have Ubuntu, Arch Linux, openSUSE, and Windows 7 on this machine, but I am using Ubuntu as the main OS and allowing it to manage GRUB and its configurations. All of the operating systems are at their most up-to-date versions. menuentry 'Arch (on /dev/sda7)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-simple-b9522736-878c-49e3-b30d-ad65589aa1d9' { insmod part_msdos insmod ext2 set root='hd0,msdos7' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos7 --hint-efi=hd0,msdos7 --hint-baremetal=ahci0,msdos7 b9522736-878c-49e3-b30d-ad65589aa1d9 else search --no-floppy --fs-uuid --set=root b9522736-878c-49e3-b30d-ad65589aa1d9 fi linux /boot/vmlinuz-linux root=UUID=ad4103fa-d940-47ca-8506-301d8071d467 rw quiet initrd /boot/initramfs-linux.img } As you can see the first two UUIDs are different from the last one. The first two are correct and the last one is wrong. If I replace the last UUID with '/dev/sda7', Then it boots without problem. I have manually edited the grub.cfg to do this, but I would like os-prober to get back to working automatically. Thanks.