Have a weird issue

I have a my passport usb drive hooked up to my wdtv and the wdtv is on my network.  At some point last night, all of my TV shows and movies stopped transferring to it.  I can access the usb drive from my desktop (play movies and delete files) but when i try to send a file to the usb drive from my desktop, it craps out.  Anyone have a similar problem?