Actually, indogulf, the restrictions on the Global Explorer fare is that it is limited to 28500 miles. You can still do: SYD-HKG-LAX-NYC-LHR-SIN-SYD. Or I managed a : SYD-HKG-JNB-LHR-SIN-SYD, without any problems.
I wonder why India does not have any rates for oneworld fares?