I also have received miles off a free ticket when being changed from say United to Varig (belong to both programs) and an uprade too boot! (Many times)

Question?
I just had a flight delayed 3-4 hours and was put on DL by NW, while I got the miles for flying DL on my Worldperks account (and the Y class bonus + my reg. 100% bonus) I still lost (1) one segment w/NW (and 100% elite bonus). Should I ask for that segment credit, or just leave well enough alone? Will NW consider such?