had similiar situation, and had it for a long time..about a year..it even become worse as every gear shifting, may require me to wait from 3-40 sec  for next shift..  untill i cant tahan coz people keep honking and cursed me for stalling them  ... the service guy also now only say something about changing the accumulator..before this he said mayb gear box problem and may cost a lot to repair. After spend rm700 for 2nd hand accumulator(1 month waranty)  now works fine just like new, i miss so much this feeling of not to worry about the gear will stuck at N or at any position...

in a mean time, if your car dont have trouble at starting the engine, just turn engine off totally and start again...faster than waiting the gearbox error light to go away.

my uncle had almost similiar problem, but he solved it by changing the speed sensor at rm200..