I have the double boot problem fixed. I updated to BIOS 1505 and pressed the CMOS reset button in the back of the motherboard for five seconds. I had to re-enter all my BIOS settings but the double boot is gone! I'ts so much nicer.
I see this is an old post but has any thing been improved with double (sometimes triple) boots on cold start up? My BIOS is flashed to 1503.
Thanks,
Edit: I found 1505 and loaded that. Still double boots.