Does the website have a seat selector?
 

I seem to recall being able to view what seats are open on a certain flight, but now I can't find it. I went so far as to booking a dummy reservation on a flight I am already booked on (via corporate travel) just to reach the point where seat selection is offered, but I cancelled out of the session because none was viewable at least until after the payment was specified.

I just want to see if my desired seat is empty before I go to the airport and ask for it (I always get 'checkin required' when booking via corporate)

I think the method you mentioned (using dummy booking) only works when you book in F or J. Previously, you can view those seat maps on www.seatmap.com. But access has since been restricted.
However, there were talks at the introduction of the non-stops that EY pax can also pre-reserve their seats. Maybe you should ask SQ about that.

I'm booked in F JFK-SIN and J on my return SIN-EWR, and not only can I not see my seats (although the res agents were very pleasant in allowing me to choose verbally which seats I want), I can't get see my res on their site, as I had to make it over the telephone. The website wouldn't allow a combo F/J to be done online :td:

mauld:
I just tried SQ website and made a dummy booking of JFK-(F)-SIN-(J)-EWR and was able to get the fare of about USD8K, and view the seat map for both sectors (outgoing in F and return in J). If you want to see which seats are still available on your particular flights, just make dummy booking in F, like I did. The SIN-EWR flight option will automatically show up in Raffles.

As I mentioned to you on another thread, "Retrieve Booking" functionality is only available exclusively for bookings made on the website. "Internet Check-in", on the other hand, is open for everyone.

From what I read on the SIN DO thread, you were applying some kind of credit towards the purchase of your ticket. Therefore, I assume you bought the ticket offline.

I hope this help. :)