Kernel with PAE does not build

[Axel S. Gruner]

Hi,

we have in our IBM x345 Server 4GB of RAM. So we need the option PAE in
our kernel. 
But a buildkernel gave me:

/usr/src/sys/dev/amd/amd.c: In function `amd_action':
/usr/src/sys/dev/amd/amd.c:466: warning: cast from pointer to integer of
different size
*** Error code 1

Stop in /usr/obj/usr/src/sys/SFBACKUP.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.

What could be the problem? 
FreeBSD 5.3-STABLE.