I wanted to extend my memory and bought a mmc card of 256Mb. First I copied (thorugh my card reader and pc) the content of the original 64 Mb card onto the new card. Then I placed it in the phone. The phone doesn't see it, gives message like 'place memory card' while mmc is in and lid is closed. It does see my orginal card when i place it back. Than I removed all files from the new card and trijed again - no success. Than I compared the filesystems of the 2 cards: both are FAT. I reformatted on the pc the new card using FAT (not FAT32). After all this the phone still doesn't see that i insert the mmc card.
I bought the card as a 'card ready for mobile phone' - that is what it said on the pack. However, on the card itself is written only 'RS-MMC' it doesn't mention 'DV'.
On my original Nokia card 1.8V-3V is written. So probably you are right - the card is suitable for phones maybe - but not for mine ...