Comment 2 for bug 736743

Confirmed here. Though my configuration is a bit different it gives the same behaviour as here above described.
I run Natty alpha3 amd64 with kernel 2.6.38-7-generic.

sudo fdisk -l responds with the following:

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x57853315

   Device Boot Start End Blocks Id System
/dev/sda1 1 13 102400 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 13 2563 20480000 83 Linux
/dev/sda3 2563 54428 416603136 83 Linux
/dev/sda4 * 54428 60802 51198976 7 HPFS/NTFS

With /dev/sda1 mounted as /boot formatted as reiserfs, /dev/sda2 is also formatted as reiserfs and mounted as /
/dev/sda3 is an ext4 partition mounted as /home and /dev/sda4 is my Windows partition.