I had the old 512 Mb Nokia SD card in device when I found out that it is not working with new firmware. I then reformatted it to FAT16 using sdformatter V3.1 (using defaults). After that I formatted it again to FAT16 with Win7 and to FAT32 using Win7. None of these was working 
The only functioning card I have (128 Mb) was found in my Garmin navigator… When I connect it to my PC it wants to scan the card for defects. I have had no courage to do so…