I cannot format a partition to Extened partion with logical drive in Vista?

I found this when I was trying to create a partition.
I have a 160GB SATA Hard drive.
The Vista system takes the first 40GB.
I tried to setup an extented partition with logical drive, in Windows Vista
mode, as I did in Windows-XP mode.
But there is no such option for me to do it.
I can only create primary partition.
So I did.

I restart the whole system, boot it up from DOS 6.0, use Fdisk tool to view
the partition which I just created.
The tool showed an error message, saying there is a partition overlap
problem with the disk.

I remove all partition except the Vista system one.
Recreate an extented partition, and with a logical drive.
It worked as usual.
When I go back to Vista, I can see the Vista system partition, the extented
partition as well as the logical drive.

This is very interesting to me.
Vista is able to take that old partition structure, but does not allow you
to create it within it.

I would like to know if there are some new things about this feature which I
do not know??

Timu