Pads only play very low????

I was working away on a project and I turned my mpc on yesterday and the pads wouldn't play...then i recorded a new sample and they began to play again but only very low,too low to hear in recording.

If i press the pads they still record, and all sequences play back perfectly. When i load other projects the pads play back as they should.
This is the first time i've had this problem.

any ideas?

From the JJ site:

"Notice 2
When you install OS2 for the first time, please perform sensitivity adjustment of a pad first."

Peace!

It happened with OS 5.48 ..still the same only with that project tho..weird