1993 Chevrolet Silverado intake manifold gasket

When I replaced the intake manifold gasket about 10 years ago I found when I took it off this time it was leaking from the front and back where the rubber seals where. I put RTV at the four corners where you where you should, but the gasket still leaked. I think the gasket got so hard over time I guess it lost it's seal. Was wondering this time on the new one would it be good to put a thin coat of RTV on both sides of the rubber seals or is that not a good idea or just use RTV with out the rubber seals, would that be better and alright to do since they came with the gasket set?