The last trading day for the March 2005 COMEX silver contract, the spot delivery month at the time, was Tuesday, March 29. That contract had a 3 cents (USD 0.03) premium (greater price than), upon expiration, over the May contract. This is quite rare and indicates that somebody (a user?) needed silver immediately. It indicates tightness in deliverable supplies.
Read Ted Butler, one of the few experts on the silver market, for the details.