[parted-devel] Confusing error when creating partition

[xerces8]

OK, can anybody decypher tihs ? :

(parted) print                                                            

Disk /dev/hda: 251GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End     Size    Type      File system  Flags
 1      32.3kB  16.8GB  16.8GB  primary   ext3         boot 
 2      16.8GB  232GB   215GB   extended               lba  
 5      16.8GB  230GB   213GB   logical   ntfs              
 6      230GB   232GB   1999MB  logical   linux-swap        

(parted) mkpart logical 240GB 244GB                                       
Error: Can't have overlapping partitions.


Version is 1.7.1-5.1ubuntu8

Regards,
David