4 gb clip zip

Have had a clip zip for the past 12 months for audio books. Great!! Purchased a 16gb sandisk card to enable more books. Can only load up one book to audiobook in card memory. As soon as I Ioad another the player will drop both from memory on player although still shows as being there on the pc in the audiobook section of card. Usb setting is msc. Shifting from u torrent via drag and drop- never had a problem with the system on the internal audiobook. Anyone else had this issue? The music loaded to card works fine so presume the card is up to scratch and there is something I am missing with the audio book side of it. Cheers Kent

Sansa Clip Zip board