If you don't use Bates stirrup leathers with a Bates saddle then you will get 'orribble rub marks on the saddle. If you use their own leathers you don't get it. We've had 3 Bates saddles & never had a problem. A friend had the same problem as you when using stubben leathers.
I have a bates caprilli dressage and the caprilli jumping saddle xD Love them both
Did find that the dressage saddle is better with the dressage leathers than normal ones, as the buckle stuck in my leg and it was umm... painful o.o But that's solved now so no problems!
Lovely leather, hard wearing, always looks good - I love the fact that the flaps are narrow, the bates Innova does nothing for me, it just doesn't suit the 'refined' look that anything dressage related should have in my opinion
Overall, a neat saddle that puts you in a good position and does it's job basically! Wouldn't swap it for anything EXCEPT a Vega dressage saddle.... heheheh