Had the same problem back in April and only just got round to arranging to send it back. Imagine my horror when I'd discovered the price had now practically doubled!!
Sorry, but it's a complete rip off. We've seen on various threads here that Kef were repairing these for free, then they introduced a £50 fee, now it's £90!! My only guess is that the system is reaching that age where more and more of them are failing and they see it as a bit of a cash cow. A three year lifepsan for a piece of hardware that the majority of audio retailers were trying damned hard to sell at nothing less than £1000 (with the exception of Creative Audio) is pathetic.
Not only that, but this is a blatant issue with the system, this isn't wear or tear or damage caused by a user, this is an obvious fault that a lot of owners are seeing. It's blatantly poor quality control and why should the consumers have to pay for it?
Also, if you read threads like this:
KEF PSW 2000 repair time
you'll see that one owner had his sub repaired for free, and this was at the end of June 2007!!
Hardly seems consistent!