Jesus Cuilionn, I just love readin' your stuff...You could write a treatise on hair follicle damage due to improper cortex nutrition and I'd enjoy it. And Bert...congrats to the engineer in you, a feature I've often found a bit disconcerting in others. Did you happen to go on reading in that previous thread about the differences in lutes vs. zithers? If you did, the engineer part should see it clearly, as you have.
Cuilionn...An Appalachian Dulcimer is a long zither, and a zither has strings running across two bridges for the entire length of the resonant body. Therefore what we have come to refer to as a "nut" is another bridge and within certain parameters, BOTH BRIDGES should be the SAME HEIGHT. It's not a guitar, mandolin, or banjo which are lutes; it's a zither. Also, be very careful when notching for proper matching of string depth and alignment on both bridges. Oughta' fix your problem!!! I think all the harp/lyre/bow/zither/lute junk was in the thread on "Playing Strange Instruments" about a week ago.