I think that we constantly grow and change. If not physically, we change mentally and spiritually.
Having a deck that works really well and then not getting anything from it could be an indicator that something has happened in our lives that makes us see things in a different light.
Say for instance that you're moving to a different place, finding yourself surrounded by a new town, new people, a new way of life.
Your old trusted deck suddenly stops talking to you like it used to. Not only is everything else new, you can't even keep your old deck?!? But then, if everything else is new - why not the deck aswell?
If your outlook on life has changed and you're moving from say a smaller town to a larger city your whole view of day-to-day life will be different. So, it's not really all that strange that the cards with images reminiscent of your life at a different pace in a different place may get you off kilter.
Maybe they work perfectly again the times you go back home and visit family and friends, but in the new setting - you may find another deck that has the easy going communication going, simply because it fits in better with 'who you are' in this new place.
Or it could be an emotional growth.
Maybe you've had a more 'romantic' deck for a few years. Then life gets you down, breaks your heart and leavs you slightly jaded. The cards no longer seem deep or profound, they no longer reach you like they used to... Instead they seem naive or bland.
Your heart and view on life may have changed - and with that your mental filter.