I can tell you what I did to overcome this, this applies to the Red Hat family and may be a bit differnt for ubuntu. First make sure you have the device configured in /etc/fstab, example;
/dev/hda1 /media/winos auto exec,noauto,user,ro,umask=0 0 0
Then make sure you (the user) is in the /etc/sudoers file with the rights to use both mount and umount, example;
%lenard ALL=NOPASSWD:/bin/mount ,/bin/umount
Notice the path is specified, it might be a good idea to also give yourself this path in your .bash_profile file (for example if needed). You may have to create a wheel group and add yourself to this group also.
$ mount /dev/hda2
$ ls -al /media/windowsxp
dr-xr-xr-x 1 root root 8192 May 31 08:36 .
drwxr-xr-x 7 root root 4096 Feb 5 16:09 ..
dr-xr-xr-x 1 root root 0 Apr 22 10:46 3a32
dr-xr-xr-x 1 root root 0 Feb 10 15:21 Acer
-r-xr-xr-x 1 root root 150528 Jun 19 2003 arcldr.exe
-r-xr-xr-x 1 root root 163840 Jun 19 2003 arcsetup.exe
-r-xr-xr-x 1 root root 0 Feb 10 14:02 AUTOEXEC.BAT
dr-xr-xr-x 1 root root 0 Feb 11 09:31 bcd
-r-xr-xr-x 1 root root 192 Feb 10 13:59 boot.ini
<snip, you get the idea>
$ umount /dev/hda2