I am unable to delete a partition using fdisk

Issue

I am trying to delete a partition called /dev/sdw8 but unable to delete it.

'fdisk -l /dev/sdw' command display:

fdisk -l /dev/sdw 
 
Disk /dev/sdw (Sun disk label): 30 heads, 128 sectors, 54612 cylinders 
Units = cylinders of 3840 * 512 bytes 
 
   Device Flag    Start       End    Blocks   Id  System 
/dev/sdw8  u          0     54612 104855040    f  Unknown

deleteting the partition /dev/sdw8.

Command (m for help): p 
 
Disk /dev/sdw (Sun disk label): 30 heads, 128 sectors, 54612 cylinders 
Units = cylinders of 3840 * 512 bytes 
 
   Device Flag    Start       End    Blocks   Id  System 
/dev/sdw8  u          0     54612 104855040    f  Unknown 
 
Command (m for help): d 
Selected partition 4 

Saving the changes:

Command (m for help): w 
The partition table has been altered! 
 
Calling ioctl() to re-read partition table. 
Syncing disks. 

When I do 'print' the partition /dev/sdw8 it still appears:

Command (m for help): p 
 
Disk /dev/sdw (Sun disk label): 30 heads, 128 sectors, 54612 cylinders 
Units = cylinders of 3840 * 512 bytes 
 
   Device Flag    Start       End    Blocks   Id  System 
/dev/sdw8  u          0     54612 104855040    f  Unknown 

root@ls1oracmdr1sb ~]# fdisk -l /dev/sdw8 
 
Disk /dev/sdw8 (Sun disk label): 30 heads, 128 sectors, 54612 cylinders 
Units = cylinders of 3840 * 512 bytes 
 
    Device Flag    Start       End    Blocks   Id  System 
/dev/sdw8p8  u          0     54612 104855040    f  Unknown 

Trying to create a new partition to see if it takes

Command (m for help): n 
Partition number (1-8): 1 
Other partitions already cover the whole disk. 
Delete some/shrink them before retry. 

So I am unable to delete the partition. How do I fix this problem.