As others noted, SanDisk MMC 64MB did not work with Intel Personal Audio Player 3000. After some struggle I found the notice on the Intel support site regarding the incompatibility, which suggested contacting the SanDisk support. I did and it was a total waste of time...I returned this product to Amazon and asked for exchange with a Viking MMC...the Viking MMC worked just fine. 5 stars for Amazon, 1 for SanDisk.