No telling what this is caused by.
It is actually very simple:
If an active system partition already exists in the system when you are installing Windows 7, the installer will NOT create a 200MB system partition.
If there is no active system partition when you are installing Windows 7, it WILL create a 200MHz system partition.
You can use another OS or GParted to create and format a new partition on the hard drive you want to install Windows 7 on and set it as active. Then, boot to the Windows 7 install DVD and install into that partition and it will not create the 200MB partition.