clip will not connect to computer

yesterday, i plugged my clip into my stereo using a cord which i normally plug into my video camera.  the cord looks the same as any headphone jack cord, and i was just seeing if it worked.  sure enough, it did and i was able to listen to music.  when i was done, i disconnected the clip and turned it off.

i can turn the clip on and off with no problems.  

when i plug the clip into the pc, the screen goes blank, even when turned on.  once the clip is plugged in, i cannot get anything to occur on the screen.  ive tried on two computers using different usb cords that have all worked before.

i did a reset of the clip, i did the reformat, i have tried all of the different usb type connections you are offered under settings.  nothing will allow the clip to connect to a computer anymore.

it is simply bizarre.  i can plug the usb cord into the clip, but the moment i plug it into the computer, the clip turns off.  as far as i can tell it is not charging when it is plugged in.  i tried the hold the power button for 15 seconds thing, and the ‘lock’ thing holdling teh center button while you plug it in.  no luck.

i just dont understand what is going on.  the only thing that i did differently was plug it into the stereo using the different cord.  that is the only thing that has ‘changed’ since i last used it.

its charging when i leaved it plugged into the computer.  so confused.