Jürgen, may I apply the attached patch to allow autoconf 2.68?
The change to libtool.m4 simply avoids the innocuous (in our case)
warnings which are now issued by AC_LINK_IFELSE if the first argument
is not conforming.
See http://lists.gnu.org/archive/html/autoconf/2010-09/msg00069.html
I tested it on solaris and it worked flawlessly.
Please wait a bit until branch is open again (I'm waiting unil we have at
least one win32 installer).