Well I now have two accounts, the only differences being account number/pwd and email address (and #1 is Silver, and #2 is Platinum).
I have a redemption certificate for the princely sum of USD60 which I 'activated' last October but could not use as planned at Sofitel Sydney as it is not valid for a prepaid booking. So I have a last chance to use it at Novotel Auckland Airport at Easter, about a week before it expires.
Travelling with two friends, and I have decided that rather than use it on my room rate, I'm going to plonk it on the bar for when we arrive around midnightish. Going to book under the Silver number as it seems like potential hassles booking under the Plat number, as the certificate links back to the silver number. I also have ~1200 points left under the silver number, so may as well add a few more. Don't exactly get much as Plat, except a few extra points.
If anyone has experience at 'merging' the two accounts I'd be happy to hear it. Otherwise I'll just build the silver to 2K points (redemption certificate) then can it and use the new one. In any case, there is not much at stake.