what surprised me is a 2003 build of BartPE succeded in creating the partition while a Gena build using 2003 as source failed .
I guess windows hotfix KB919117 do rest of adjustments on 2k3-XPx64http://support.microsoft.com/kb/919117let me know if you can make a plugin (batch .reg etc. ;) all fits ) for that... (and maybe you can also find a test routine to validate..)
Creating and formatting partitions from disk management works fine when "small core build" is disabled (2003 source) .
( 2 TB + disks probably won't be supported ).