Yamaha DTXpress/DTXplorer/DTXtreme

I have the DTXtreme IIs with the snare drum pad TP120SP.
I have found that if I am playing real hard on the bass pad that i find 
the snare will not play. I have set the self Reject set to 10MS and 
Reject set to 0.
I need the snare to play every time.

Thanks for any help.
James