Carphone Warehouse first as your warranty should be from them (as they sold you the phone in the first place). If you have major issues with them, then try with Nokia directly.

I bought mine from Vodafone online, and collected it in-store, but figured I was better off sending it to Nokia directly (as their online checker insisted it was still under warranty) as Voda don't stock the N900 any more, plus it's awfully hard to track where your phone is (so I have heard) if you take it to Voda and they'd probably have just sent it to Nokia on my behalf anyway?

My 14 month old N900 has recently taken a dislike to charging via the mains, but will charge by USB, and with an "old" style Nokia charger with a mini-USB adaptor on the end... would this suggest USB fail is imminent? I'm looking to upgrade soon anyway, but obviously it'd be nice to be able to sell on a brand-new N900....! (Incidentally - I've always had Nokias... 5110, 3310, 8310, 7250, 7610, N70, N95, N96, N900... and I'll be ditching them for now as there's nothing on the way that interests me )

Does this usb port problem exist in other devices which has the micro usb port, as well? or the problem is only with N900!?

I got mine off two days ago, gonna order connector and reattach it, the question is how do i protect myself from this happening second time? is there a way to re-solder it and secure the connection of usb connector?