After all, this was due to a Bios bug in the P5Q Pro motherboard. Solved by updating the bios.
** Changed in: grub (Ubuntu) Status: New => Invalid -- Grub very slow to start on sata hard drive, asus p5q pro motherboard https://bugs.launchpad.net/bugs/298503 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