AdNauseam,
I'm not familiar with the Duraplane in general, but I'll try to help. Which way is the trailing edge warped and by how much? Foam is pretty soft, so you may be able to take some of this warp out. As you look at the wing from the top, the trailing edge should be pretty straight. You want your the area where your ailerons are hinged to be pretty straight so they work well. Sometimes when the foam blanks are cut out, the trailing edge doesn't come out exactly right. Some trimming/sanding may be necessary. You might try trimming it with a knife and exacto or sanding it straight with a long sanding bar. Be careful not to change the overall shape of your airfoil though.
If the trailing edge is straight along the chord, as described above, and merely warped along the span, you shouldn't have too much to worry about as long as it's minor. Attaching the ailerons should take some of this warp out. If it's really bad, you might try inlaying some hard 3/16" square balsa into the trailing to straighten it.
I'm not sure I completely understand your problem, but I hope this helps.

Jason