hmm, I have a no-name micro to mini SD adaptor. I also have a Sandisk 4Gb micro SDHC card. I'm guessing the no-name part is also Sandisk hence the fact it won't work in the N810 (the micro SD card is itself good though as it works with the Sandisk micro to full SD adaptor in my N800).

So, I see TopRAM adaptors work, what else are people using as I can't seem to find TopRAM adaptors in the UK except ones shipped from Taiwan via eBay?