AMD 64 Status

I was just wondering about the status of AMD 64 support, before I
spend a lot of time with it. I can't get it to install using the
snapshot: AMD64 7.0 200706 with an Athlon 64 X2 processor. The last
thing it says before it bites the dust is:

Trying to mount root from ufs:/dev/md0
start_init: trying /sbin/init
start_init: trying /sbin/oinit
start_init: trying /sbin/init.bak
start_init: trying /rescue/init
start_init: trying /stand/sysinstall

The i386 distribution installs and runs OK on the same processor. Are
there known issues with installing the AMD64 distribution?

Thanks,
Larry.