Error: partition to partition installation

[hirura]

An error occurred when installing pfsense 2.0 RC3 from partition to partition.

I have a computer FreeBSD OS installed.
The OS is installed in ad0s1, where this hdd has three patition: ad0s1, ad0s2, and ad0s3.
Then, I downloaded pfSense-memstick-RC3-i386.img
And I copied the disk image to another partition with the following command:
dd if=pfSense-memstick-RC3-i386.img of=/dev/ad0s3
where ad0s3 has an enough space to dd.

After Rebooting, I selected ad0s3 to boot from pfSense image.
I succeeded in booting with it.
And I tried installing the pfsense to the ad0s2 partition using "custom install" option.
But during installation, an error occurred.
Cos my HDD has the partition, I skipped formatting, partitioning, boot block installation.
And I choosed ad0s2 partition and began installing.
Then, "Cancelled Execution of the command /sbin/bsdlabel -B -r -w ad0s2 auto FAILED with a return code of 1." message is showed.
The log massege is
"Executing '/sbin/bsdlabel -B -r -w ad0s2 auto'
bsdlabel: cannot open /boot/boot: No such file or directory
Exit status: 1"

Can anyone solve this?