Mornings at WGNU (920 AM) were a little quiet in July. Absent was the voice of Lizz Brown, host of The Wake Up Call. Then again, Brown had a pretty good excuse for her absence: She was stuck in Ghana. Along with 72 companions, Brown had journeyed to West Africa on a trip organized by a Brentwood-based travel agency. But what was meant to be a quick group tour turned into a multi-week nightmare when the United States government prohibited Ghana Airways -- the only direct link between Ghana and the U.S. -- from operating in this country. The tourists were trapped, not to return until -- under pressure from the U.S. government -- the airline ponied up for a couple of charter flights home.