Samsung SGH-D900 / Black Carbon

my son has the same phone & we are having identical problems - we purchased a Kingston 1Gb card, had it replaced & exactly the same problems - msg from Kingston supplier - phone supports max 512Mb - msg from Samsung South Africa is that they know the phone has been tested with Sandisk card - finding it very difficult to accept all this - phone presently taken in to be checked out with the 1Gb Kingston card - still waiting for feedback - all very disappointing