I had to break with my “Some interesting…” title tradition. “Some interesting worst bug in Dapper” simply makes no sense at all😉
If you sort the Installation and Upgrade section according to most views (or to most replies) like this.
Then it becomes evident that the “booting stalls during mounting root filesystem” bug is by far the biggest showstopper.
This bug is probably (most of the time?) related to people who have both SATA and PATA controllers on their motherboard. The bug shows both after upgrading and installing. The bug manifests itself in different ways and has different solutions. So it’s also possible that this is a class of related bugs or something.
What happened in my case :
For me my /dev/hda became /dev/hde after upgrading. On a fresh install I could produce exactly the same results. To solve it I had to edit my /etc/fstab and /boot/grub/menu.1st accordingly. Each time a new kernel gets installed I have to edit my /boot/grub/menu.1st again and change /dev/hda for /dev/hde.
See for example a part of my /boot/grub/menu.1st : title Ubuntu, kernel 2.6.15-25-686 root (hd0,5) kernel /boot/vmlinuz-2.6.15-25-686 root=/dev/hde6 ro vga=0x31a quiet splash initrd /boot/initrd.img-2.6.15-25-686 savedefault boot Mind the line :"root (hd0,5)". So grub needs the (translated) parameter /dev/hda6 while the kernel needs it to be /dev/hde6.
But as I have said before. This bug manifests itself in different ways and has different solutions. I compiled a list with some fixes.The last thread is the big discussion thread where people post their problems.
booting stalls during “mounting root filesystem”?
udev enumeration should use /sys/bus not /sys/devices
The developers know about this bug and we might see a dapper-update someday. See this thread : http://www.ubuntuforums.org/showthread.php?t=208207