Don't use pushd/popd in autogen.sh; Ubuntu's /bin/sh doesn't support it.
diff --git a/autogen.sh b/autogen.sh
index 3e958e1..9edfb8a 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -5,7 +5,7 @@ echo "This may take a while ..."
srcdir=`dirname $0`
test -z "$srcdir" && srcdir=.
-pushd $srcdir
+cd "$srcdir"
# Regenerate configuration files
cat acinclude/* >aclocal.m4
@@ -19,7 +19,5 @@ if test x$found = xfalse; then
fi
(cd test; sh autogen.sh)
-popd
-
# Run configure for this platform
echo "Now you are ready to run ./configure"