Northwest just integrated its flight #s with delta, however, every time i try to put in the new #, it comes up as a flight operated by Pinnacle. How can I fix this?
All of the codeshare partners, Mesaba, Pinnacle, Comair, etc. always show up under their own company name and callsign. Even though your airline ticket will show Northwest flight 2720, ATC will use Mesaba 2720 as the aircrafts identifier.
no this is a mainline flight. the one im looking at is flt. 2359 from DTW-MSP on an A320. It’s previous # was 1457. When I search by origin/destination, it comes up with this new flt. # but when I click on it it still goes to the pinnacle flight.
I just searched for NW 2359 and the flight showed up.
oh i guess it must have just gotten changes. oh well thanks for the help guys! 
I tried doing it the way you described and it came up with the proper flight number for me as well. Try clearing your browser cache?