chilly water

Yeah - same thing has happened with 3 different disks...

I've got a Sony MZ-N707 It's not been used that much. But what is happening is: I record something with an external mic. The time counts up, I get levels. I can play it back and hear audio. It'll say Data Save and TOC Edit. When I take it out of the player and put it in another player, it tells me Blank Disc. When I put it back into the N707, it says Blank Disc. Where is my audio going? Is there a setting that I've screwed up, or is this thing just fried? Thanks for any and all help.