I have a RCA pearl

Question

I have a RCA pearl th1100A and im using yahoo music jukebox to transfer music to it and when i look to see how much free space i have it says 419 mb. My mp3 player holds 467mb. Even though i have 419mb of space left it wont let me add any more music and says that its full but everytime i delete songs from the mp3 player it lowers and lowers the amount it will let me transfer onto it. But i dont know how to fix it. so how can i fix it?