The Court of Criminal Appeal in Dublin has quashed the appeal of Mary Kelly, who was convicted in 2004 of criminal damage to a US military aircraft at Shannon Airport.
However, her tresspassing charges have been reserved.
Her appeal was heard on July 29, 2008, and no explanation has ever been given as to why it took more than two and a half years to deliver the judgment.
This first trial resulted in a hung jury on July 4, 2003.
The State subsequently retried Ms Kelly and she was convicted in Ennis Circuit Court under Judge Carroll Moran on October 29, 2004.