Grundy County Schools Superintendent David Dickerson has decided to resign his post after nine months on the job.  School Board sources tell Eyewitness News that Dickerson had decided he is more comfortable in a school setting.  He had previously served as a principal at various Grundy County Schools, and had also served as superintendent for a brief period of time several years ago.  Dickerson's decision is said to have taken several Board members by surprise, and there is no information as to a possible successor or interim superintendent.