Veteran rocker David Crosby has postponed a forthcoming US tour with former bandmate GRAHAM NASH because of a mystery illness. THE CROSBY, STILLS AND NASH stars were due to hit the road next month (MAR07) for a series of gigs across America, but they will now be rescheduled. Crosby, 65, has battled ill health for years. He has hepatitis C and underwent a liver transplant in 1995. He also cancelled an Australian tour earlier this month, amid claims he was suffering pneumonia. A message posted on crosbynash.com reads, "We deeply regret that the band will not be able to embark on this (U.S.) tour as scheduled. The action was taken because of medical issues that have arisen for member David Crosby. At this time, we thank you for your understanding and the band looks forward to seeing you this fall."