Memory - removing iTunes does not free up memory space

I have 4G Clip. Followed instruction to transfer iTunes into clip and mostly works great. However, at some point (likely a corrupted or protected music file, is my guess), the Clip chokes and turns off.  I reset and when it does it’s media check, it chokes again adn turns off. I reset again and plug into Mac to remove recently added media and everytime I disconnect, the media check gets worse and worse.  Eventually, I end up deleting all the media I’ve added and the media check goes great. But I’m left w/less memory and no tunes. I’ve been through this several times and am down to only a few MB. I don’t know what causes the choke as it appears to happen when transferring different songs (as far as I can tell). So the choke is one problem and not easy for me to tell why it’s happening.  Resetting or deleting NOT restoring my memory capacity is another.  I want access to this memory again (and I’ll transfer mp3s and give up on my itunes). Any ideas on how to make clip notice that there is not stored media anymore?

Format it.