Ooh, now I see what you are doing. I got this CSM working with a 16F727 and other chips but not in sleep mode. It is good to know that it works in sleep mode. Don't you have inaccurate value readings with the WDT as the timeframe interrupt? I read somewhere that the WDT is not too accurate.

Also, you said that you are using WDT intervals of two seconds. I didn't know you could go that high. I guess that a quick touch is not going to be detected by your device. I have used intervals in the order of a few milliseconds.