Prison breakBy Bruce Alpert and Bill Walsh Sunday, February 24, 2008 Vernon Jackson and Brett Pfeffer, key figures in the federal prosecution of Rep. William Jefferson, D-New Orleans, were released recently from federal prison -- but it was only temporary. Their release from federal prison facilities in Pennsylvania and West Virginia was ordered so that they could testify at Jefferson's federal corruption trial. But with the trial, which had been scheduled to begin Monday, postponed while a federal appellate court considers an appeal of a pretrial ruling, from Jefferson's attorneys, it's likely they will be returned to their prison cells...