e@ebox:/media/sidux1/boot$ sudo fdisk -l

Disk /dev/sda: 750.1 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00031489

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1       45612   366378358+  83  Linux
/dev/sda2           88245       91201    23752102+   5  Extended
/dev/sda3   *       45613       88244   342441540   83  Linux
/dev/sda5           89724       91201    11872003+  82  Linux swap / Solaris
/dev/sda6           88245       89723    11880004+  82  Linux swap / Solaris

Partition table entries are not in disk order
e@ebox:/media/sidux1/boot$ cat grub/device.map 
(hd0)   /dev/sda

(11:37:56 AM) devil: blaamann: yes, i would reinstall. install ubuntu first, grub to mbr, then sidux, grub to partition. then chainload sidux in ubuntus menu.lst