Weird installation issue

Hello,
I recently wanted to update FreeBSD on my computer to latest version, 
but now I am facing weird problem. After completing installation from 
dvd I can't boot into BSD. I naturally assumed this is some boot 
manager/boot sector issue, and since I am using Vista also (but on the 
other hard disk) I first overwrited its boot manager with FreeBSD's but 
without any luck (when I press F2 to start BSD machine either stops to 
respond or prints # for any keypress, no any messages from BSD 
bootloader). After that I tried to make BSD entry in grub from open 
solaris but with the same symptoms (freezing without any message on the 
screen). I also tried installing GAG boot manager but with the same 
results.
When I open BSD's partition using some hex editor boot sector seems 
written correctly. Also if I boot fixit prompt from dvd I can mount 
partition from hard disk (I tried only mounting a partition where is /) 
everything looks written correctly. However if I escape to loader prompt 
at dvd during boot and set currdev to "disk1s1a:" when I issue ls 
everything freezes.
I believe this is some booting issue on my machine, but I am loosing 
ideas what can I try next.
Please advise what I should try (FreeBSD is my first choice for UNIX and 
now I am stuck with open solaris)

Ivan