930GB in 1TB My Book essential after disabling the VCD?

I disabled the SmartWare VCD on my new 1TB My book essential (just out of the box) fusing instructions from the following page http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=3835. I see one drive with 930GB free. Is that fine. Should’nt I be seeing 1000 or 1024GB??

Under XP/Tiger/Leopard 930GB.

Under Win7/Snow Leoaprd 1TB.  Not certain with Vista.