There was zero availability on CPH-SIN a couple of weeks ago - all marketing related to inflight Internet had been pulled too, so I suspect they had some technical problems on this particular aircraft.
Anyway, really a major inconvenience when you've already become semi-reliant on inflight Internet!
In fact I primarily chose SK because of this, otherwise I much prefer the SQ nonstop. (except for the crummy dep time from CPH)