Sprogs 4th Gen, 20gb HP Branded iPod (purchased Xmas 2004 started to die - the hard drive started failing in September 2005. Contacted HP support - no deal. They warrany for a year, from the date of manufacture. And only in the US. Eh ? So - dont buy an HP branded iPod.
Nothing to it but to open the bugger up and replace the hard drive. Surprisingly easy, even given the snug fit between the plastic front panel and back metal case. This guide really helped... And whilst I replaced the drive with exactly the same model as came out (driven by conservative stupidity, I guess), you can stick in larger drives..
So now I'm a qualified iPod engineer. Cool.