The answer of a personal mail:

> But I'm having some questions, I hope you can answer it.
> Do you have the 64-bit-version of FreeBSD-SMP running?
> And is the "userland" running without problems?
> Do you have problems with the gigabit-NIC (bge), or does it
> work "out of the box"?

a) 64-bit-version FreeBSD-SMP works.
b) userland works flawlessly. 
c) bge0 works w/o problem.

Some Notes about the used memory-sticks:
Century-Micro 512Mb PC2700 with
DRAM
NANYA 0303
NT5DS64MBT-6K
23560BPT

and with ECC chip 
CCP174SSTVF
16857A
A503110C
WORKS!


with ECC chip
Hitachi 2M4RCDCV857
_DOESN'T WORK_