<font face="Verdana, Arial, Helvetica, sans-serif" size="2">So, for the pros: why did my flight credit show up as two separate segments? From the above discussions, it doesn't sound like the plane change triggered this. What about the date change (20-21 Nov)? What about the different seats? </font>
Just luck, I would guess. Maybe one of our UA employee friends can shed some light.
I flew the same flight(s) myself on November 26 (UA 837 SFO-NRT-BKK). Had different seat assignments on the two segments. The departure dates for each segment were different, of course! But I received only 7,924 miles. (I knew about this in advance and it doesn't hurt my plans to make 1K using the Double EQM offer, so I didn't bother to try to do a "split" to get the 87 extra flight miles in each direction.)
Kathy