Boot loader configuration for FreeBSD 5.1

[Nikhil Kale]

Hi,
  I have installed FreeBSD 5.1 /dev/hda3 on my computer.
I also have linux installed on /dev/hda1 partition
While installing FreeBsd, I chose 'leave MBR untouched' option, and configured Lilo boot loader to 
boot into /dev/hda3 for FreeBSD.

 When I select FreeBSD, it shows me the FreeBSD boot prompt which gives me options like
  1. Boot FreeBSD [default]
  2. Boot with ACPI disabled
  ... and so on

  I am facing a problem, sometimes when I press 2 for booting with ACPI disabled, the system just hangs. The console freezes and even pressing 'Ctrl+Alt+Del' doesnt
do anything. I simply have to hardboot.
 This happens inconsistently .. say about 3 times out of 5.
  How can I prevent this????
Also, How can I change my default boot option in my FreeBSD boot loader to boot into option "2-Boot with ACPI disabled"?

Any kind of information would help.
Thanks,
Nikhil.