The attached patch (+ autoreconf) should fix the problem.
-- Andreas Henriksson
--- gvfs-1.6.1/configure.ac.orig 2010-05-25 15:46:41.000000000 +0200 +++ gvfs-1.6.1/configure.ac 2010-05-25 15:47:02.000000000 +0200 @@ -243,7 +243,7 @@ if test "x$enable_gdu" != "xno"; then PKG_CHECK_EXISTS([gdu >= $GDU_REQUIRED], msg_gdu=yes) - if test "x$msg_gdu" == "xyes"; then + if test "x$msg_gdu" = "xyes"; then PKG_CHECK_MODULES([GDU],[gdu >= $GDU_REQUIRED]) AC_DEFINE(HAVE_GDU, 1, [Define to 1 if gnome-disk-utility is available]) fi