Buildworld failure with -j24 and ZFS on GPT on Core i7-860 system

I typically buildworld with a parallel make of hw.ncpu * 3 which results in
-j24 on my new system (Intel Core i7-860, 8GB RAM).

I've not been able to buildworld natively on this new system (with ZFS - I
have not tried non-ZFS natively yet) but have been able to buildworld in a
virtual machine under Windows 7 64bit VMware Server 2.0.2 with 2 virtual
CPUs (hence -j6 for buildworld).

Both 8-STABLE 32bit (this VM is non-ZFS) and CURRENT 64bit (a ZFS system)
will build as a VM (-j6) but a native 64bit FreeBSD CURRENT (ZFS) fails.

The CURRENT 64bit systems were installed from the allbsd.org JPSNAP DVD of
18 Jan 2010 and both can successfully buildworld with -j1 (Virtual and
native).

Build failure is:

sh /usr/src/tools/install.sh -C -o root -g wheel -m 444  asn1_err.h
/usr/src/kerberos5/lib/libasn1/../../../crypto/heimdal/lib/asn1/heim_asn1.h
cms_asn1.h rfc2459_asn1.h krb5_asn1.h pkinit_asn1.h pkcs8_asn1.h
pkcs9_asn1.h pkcs12_asn1.h digest_asn1.h kx509_asn1.h
/usr/obj/usr/src/tmp/usr/include
sh /usr/src/tools/install.sh -s -o root -g wheel -m 444     libasn1.so.10
/usr/obj/usr/src/tmp/usr/lib
ln -fs libasn1.so.10 /usr/obj/usr/src/tmp/usr/lib/libasn1.so
1 error
*** Error code 2
1 error
*** Error code 2
1 error
*** Error code 2
1 error

I guess this is a FreeBSD ZFS bug of some kind.
I have not yet prepared another non-ZFS hard disk for native testing (though
I do have a spare hard disk available and will test this soon).