Hi, I had exactly the same problem with my e280 … wouldn’t fully charge through the PC’s USB socket even though it was showing ‘charging’ all the time. I don’t think the current available from some computers is enough to fully charge the player.
Bought an AC charger from Maplins (in UK) and everything is fine. It gives 1000mA of current. http://www.maplin.co.uk/Search.aspx?criteria=L11BR&source=15&SD=Y It comes supplied with international adaptors and you can mail order, so overseas shouldn’t be a problem. It costs £10 here.
Hope this helps, Woody
