[griffin]

if the connection between player and pc shows zzzzzzz, are you also having problems transferring the files from the PC into the player ?

I spent a week fiddling with my player because of a problem similar to what you described but i was also getting intermittent connectivity to several PCs. Then finally it stopped charging at all from charger and from PC. No green LED was lighting on the charger. I was about to change the battery, blaming it for all the mishaps. Last weekend however I decided to try a different USB cable and this resolved all my issues. Today it connects instantly and charges well.

If you notice that the usb cable slides in without any effort and does not secure properly into the mp4 player port but there is a lot of sideways movement, try replacing it, the new cable I got fits securely in place and needs some pressure to plug into the player port.