I have installed windows on a 500GiB Seagate SATA Disk, (on a new EFI computer) and once windows was all setup, I plugged my Ubuntu (11.10 x64) HDD in and booted it. All works fine, apart from when I try to access data from the windows partition:

**WARNING**: The partition is misaligned by 3584 bytes. Thus may result in very poor performance. Repartitioning is suggested.
It doesn't appear to see the two (windows boot/recovery and windows system/data) partitions there. Is there any way that I can get the system to recognise (mount) the partition(s) without re-installing Windows?
EDIT: GParted appears to pick the partitions up, but complains:
Oh, and /etc/mtab does exist.
EDIT2: Booting from a 11.04 x64 Live cd, The drive can be mounted through nautilus fine and GParted does not report any errors.
EDIT3: I ended up wiping and re-installing both OSes, as Ubuntu was doing this (which does not occur with a new, un updated install) and windows was refusing to boot with another drive plugged in. Thanks for the help!
dmesgoutput about the problem drive? – James Henstridge Apr 17 '12 at 4:54df -handsudo fdisk -l? Do you have these problems if you boot from a Live CD/USB? What version of Ubuntu are you working with? – irrational John Apr 17 '12 at 5:01WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.– NRoach44 Apr 17 '12 at 5:13dmesgoutput. – James Henstridge Apr 17 '12 at 7:33