16 level tuning problem

Hi, wonder if anyone can show me where I am going wrong. I have had the MPC4K for a rew weeks, still learning this beast, but Im liking the results I am getting.
My problem is when I am in a sequence and I select 16 levels, then choose a sample, then select tuning, then return to the sequence. When I hit the pads there is no sound? any Ideas? if I enter program edit with the 16 levels still on it works? am I doing something wrong?
I have the latest OS installed.

I found the problem, I have been importing Midi files from my MPC2500 and I think the sequence I was working on has some problems. I have tried the tuning from a fresh start and it was fine.