Bob,
I just lost a bunch of leaves on my Darlingtonia and S. psitticina.
After some thinking, I traced it back to an application of Malathion
bug-spray. It took about 2 weeks for them to actually succumb.
Only the particular leaves that were sprayed died. Other shoots
that had come up after the spraying were unscathed.
I am going to take the Malathion to our city's toxic waste disposal
program. I'm pretty sure it also nailed a D. cuneifolia also.
It is rumored that Diazanon <sp> is a CP-safe alternative.
The only other suggestion is that you might have an insect larvae
eating out the crown of your plant. Maybe if you poke around in
the sphagnum you can check this out.
-- Rick