Fuze fails to delete old recordings: Any new solutions?

Tape

I have WMP 10.

I use the recorder mainly to record my child.  I’ve got a large archive of recordings from the time he was an infant.  I’m sure if I had a separate recorder I would not have nearly the amount of recordings that I have.  I can pull the fuze out of my pocket and record very surrepticiously.  Since I often am goofing with the device anyway, he doesn’t really notice it much and it allows me to get candid recordings.