  A D-dimensional gravitational model with a Gauss-Bonnet term and the
cosmological term Lambda is considered. Assuming diagonal cosmological metrics,
we find, for certain non-zero Lambda new examples of solutions with an
exponential time dependence of two scale factors, governed by two Hubble-like
parameters H > 0 and h < 0, corresponding to submanifolds of dimensions m and
l, respectively, with (m,l) = (4,2), (5,2), (5,3), (6,7), (7,5), (7,6) and D =
1 + m + l. Any of these solutions describes an exponential expansion of "our"
3-dimensional factor-space with Hubble parameter H and zero variation of the
effective gravitational constant G. We also prove the stability of these
solutions in the class of cosmological solutions with diagonal metrics.
