I think this is pretty bad.

Logging on to my booking on the Singapore Airlines website and trying to select a seat, the seat map is pretty much full with only a few middle seats available for selection and the rest of the map blocked.

Logging on to my booking via the Singapore Airlines iPhone app - the seat map is mostly open and I can select a seat throughout almost half the plane! (which I did and it's confirmed on my booking now).

hmmm.