On the eve of the first meeting of a lay panel reviewing how U.S. bishops punish alleged abusers, advocates for molestation victims said yesterday that the national policy for disciplining sexually abusive priests isn't being consistently followed.  Under the policy adopted June 14, priests are to be removed from the ministry as soon as allegations of abuse are found credible.  David Clohessy, executive director of the Survivors Network of Those Abused by Priests, cited several cases and said the church was violating the spirit of its policy by fighting in courts in Lexington and Louisville, Kentucky, to keep sexual abuse cases sealed or to have them dismissed.