Yamaha DTXpress/DTXplorer/DTXtreme

Geez - this site looks comprehensive - to a scarey sort of level! I 
recently bought a DTXII and so far I love it. But . . .
yesterday I reverted to the 'factory' defaults and I seem to have 
lost a few of the preset kit sounds. Has anyone else had this 
problem - and any tips on how to rectify?
The other thing that's happened is my kick drum now seems to 
have all sorts of sensitivity that it didn't have before - going from 
very soft to quite punchy even though I'm using a constant weight 
of hit from my pedal. Any ideas would be most appreciated.
Mark.