Sansa Fuze V1 odd charging problem

[Jomega1]

Hi - my beloved Fuze V1 won't charge on any source - PC or mains charger. It's the same with three different cables.

Here's what happens

- Battery shows, say, 45% charge. I plug in charging cable and charge displayed drops to about 9% and doesn't increase. When I remove charge cable the 9% returns to 45% (or less). I can play when connected, but it's not charging.

I thought it was a duff battery, so I have just put in a new one, but the symptoms are the same (it came with 57% charge).  I can boot and play when NOT connected, but the battery's running out again.

It does the same when in Sansa OS or Rockbox.

Any ideas would be most welcome, or is it the end of the road for my Fuze?

Cheers