Seating chart from Orbitz and Seatguru differ?
 

I'm flying from IAD to SEA non-stop on United in August (4months away).

to seatle, it's a Boeing 752.
Orbitz says the plane has 40 rows.
Row 33 is completely booked already? and there are people sitting in row 34. it's empty between rows 26 and 32.

Seatguru has this: http://www.seatguru.com/airlines/Uni..._757-200_A.php
It's only shows 34 rows?!


Coming back to Dulles, it's an Airbus 320.
Orbitz depicts the plane as having 37 rows and 2 isles like this:
ABC D EF

so people in Row D sit alone?!
and again Row 33 is filled already. and some people are sitting in Rows 34+35. it's empty between Row 23 and 32.

Seatguru shows 26 rows and 1 isle: http://www.seatguru.com/airlines/Uni...irbus_A320.php


Why the differences?
And What's so special about Row 33?

Sounds like you are on Continental equipment. I also suspect that Orbitz has not updated their systems and is showing a Boeing 739 as an A320. CO often skips blocks of seat numbers and Orbitz's systems are a bit confused. With lots of CO management taking over, perhaps their UA seat numbering system is being taken over by the CO scheme.

WChou is mostly correct. In June, United and Continental are standardizing seat numbering on United A320s and most 757 aircraft. The OP's flights are still scheduled to be operated by United equipment, but with some seatrow numbering changes.

This thread in the (pre-merger) United Mileage Plus forum explains the changes:
http://www.flyertalk.com/forum/unite...eff-6-9-a.html

The difference in the two seating charts is that seatguru gives you today's seat map for an aircraft; but an airline or booking engine can give you the seating chart for the flight on the day it's set to operate, if you search under those criteria. United can make equipment changes between now and then, though. If you check the United website for August flights, you'll see the projected numbering.

Update: Seatguru now has United seating charts for pre- and post-June 9, 2011, A320s and B757s.