FreeBSD freezes on boot

[Gravita]

Hey,
I installed on my FreeBSD 7.2 Root with 8GB RAM the
PAE-Kernel.

I had set the loader.conf so:

- geom_bde_load="YES"
- geom_ccd_load="YES"
- geom_stripe_load="YES"
- geom_vinum_load="YES"
- geom_mirror_load="YES"

At boot I geht this error:

mountroot>

After this, i type this:

mountroot>ufs:/dev/mirror/gm0s1a
[...]
Enter full pathname of shell or RETURN for /bin/sh:
#fsck -y /dev/mirror/gm0s1a

and this

#fsck -y

and at the end

#exit

It comes again.
After reboot to.

What should I do?
I had reinstalled FreeBSd many times,
but everytime after installing PAE Kernel
it comes.

I can't use 64Bit.

Best regards,
Gravita