External drive partitioning problems

[Robert Moskowitz]

I just got a LaCie 1Tb USB drive.  I want to delete their 10Mb NTFS 
partition then create one 1Tb EXT4 partition.

When I DiskUtility I get the following error when I try to delete the 
NTFS partition:


Error erasing: helper exited with exit code 1: In part_del_partition: 
device_file=/dev/sdb, offset=400886272
Entering MS-DOS parser (offset=0, size=1000204886016)
MSDOS_MAGIC found
looking at part 0 (offset 400886272, size 10484736, type 0x0c)
new part entry
looking at part 1 (offset 0, size 0, type 0x00)
new part entry
looking at part 2 (offset 0, size 0, type 0x00)
new part entry
looking at part 3 (offset 0, size 0, type 0x00)
new part entry
Exiting MS-DOS parser
MSDOS partition table detected
got it
got disk
got partition - part->type=4
refusing to delete a protected partition


If I just try and create an EXT4 partition on the remaining 990Gb I get 
the following error:

Error creating partition: helper exited with exit code 1: In 
part_add_partition: device_file=/dev/sdb, start=411371008, 
size=999793515008, type=0x83
Entering MS-DOS parser (offset=0, size=1000204886016)
MSDOS_MAGIC found
looking at part 0 (offset 400886272, size 10484736, type 0x0c)
new part entry
looking at part 1 (offset 0, size 0, type 0x00)
new part entry
looking at part 2 (offset 0, size 0, type 0x00)
new part entry
looking at part 3 (offset 0, size 0, type 0x00)
new part entry
Exiting MS-DOS parser
MSDOS partition table detected
containing partition table scheme = 0
got it
got disk
new partition
Error: Too many primary partitions.
ped_disk_add_partition() failed


What can I do here????