4GB Sansa Clip Stopped Loading Music

Today my 4GB Sansa Clip, not purchased a month ago, stopped letting me load files.
I can see it - it’s recognized as being connected by the computer, and the device itself says it is connected.

I can delete all the files I want, change all the folders I want, however when I try to add music I get an error message reporting:

‘Cannot Copy: The device has either stopped responding or has been disconnected’

Can someone help me with this issue? 

Same exact problem with C250  … and no help at forums or FAQ resources !?!

Display says “Connected” and XP sees it as a “drive” - but won’t load non-DRM MP3’s.

Formatting, updating firmware (already current), setting MSC mode, forcing drivers re-install - all have NO effect.

Workable suggestions, please  …  Anyone??

Had the same problem.  I just unplugged it from my computer and then reconnected and it worked fine.

Really don’t understand why!!!