In MS-speak (Disk Management flags)
"boot" = The system that's running.
"system" = Where all the boot files are
You cannot boot from a logical drive (logicals cannot be "active", and the MBR looks for the "active" primary partition), hence the placement of your boot files on the only primary.
DId you delete the XP entry from the BCD and let EasyBCD auto-configure it when re-added ?