There seems to be some errors with postal code geocoding for Mumbai, India. The postal code divisions are there, but the coordinates are spread all over India - I can't see an obvious pattern or correction that could be made.
Try 400049 (Juhu) or Vile Parle (400057 east and 400056 for west). These are scattered across the sub-continent, despite being walking distance apart in real life!
The database has these coded with an odd spelling for Mumbai, which may be because the codes are known to be wrong already:
Admin1=Maharashtra Admin2=Mumbbai
Apart from that, other Indian postcodes I've checked have been spot on, and South African ones too generally (except some odd Cape Town ones). Keep up the excellent work!
Thanks for your feedback. There was indeed a problem with the administrative divison in the Indian postal code dataset. I have corrected the administrative division as best as I could. There are still a couple of postal codes in Bihar not properly geo referenced, since Bihar seems to be missing in the toponym dataset for India (nga). Is Bihar imporant and urgent for you?
The postal codes for the city of Mumbai should now all have the same lat/lng.