Knebworth, the stately home which has rocked to Led Zeppelin, Pink Floyd and Oasis, faces a "huge hole" in its finances after the cancellation of a festival to have been headlined by Queen.Martha Lytton-Cobbold, who manages the gothic Hertfordshire mansion which has been home to the Lytton family since 1490, is counting the cost of the decision to axe Sonisphere, a three-day heavy rock event which was due to take place in July. Poor ticket sales contributed to the cancellation of the festival, which was to have been headlined by Queen, with their...