Cannot save site as template SharePoint 2010 Exporting List Announcements error

SharePoint 2010 is our first environment, there have been no migrations from 2007.

I am having a problem saving a site as a template.  When saving the site as a template, I get an error that says "Error exporting the list named "Announcements" at the URL: Lists/Announcements

I have removed all templates from the solutions gallery.  I have also deleted them from the recycle bin and the site collection recycle bin-there is no trace of another solution in the site collection.  

I have moved the solution from my development environment to the production environment, but they are setup the same-different farms.

Thank you for your assistance in advance.

Additional logging information I found says this:

SPSolutionExporter: CDATA inside CDATA blob

SPSolutionExporter: System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.SharePoint.SPContentType.Serialize(XmlTextWriter xwtr, Boolean needsFields, Boolean isForDb, Boolean useParentContentTypeIdForList, Boolean includeOverwriteAttribute, Boolean includeVersionAttribute, Boolean tokenizeTemplatePath)    
 at Microsoft.SharePoint.SPSolutionExporter.ExportListContentTypes(SPList list, XmlWriter schemaWriter, ListExportSummaryInfo summaryInfo)    
 at Microsoft.SharePoint.SPSolutionExporter.ExportList(SPList list) at Microsoft.SharePoint.SPSolutionExporter.ExportLists()

SPSolutionExporter: Microsoft.SharePoint.SPException: Error exporting the list named "Announcements"
 at the URL: Lists/Announcements    
 at Microsoft.SharePoint.SPSolutionExporter.ExportLists()    
 at Microsoft.SharePoint.SPSolutionExporter.GenerateSolutionFiles()    
 at Microsoft.SharePoint.SPSolutionExporter.ExportWebAsSolution()Microsoft.SharePoint.SPException: Error exporting the list named "Announcements"
 at the URL: Lists/Announcements   
 at Microsoft.SharePoint.SPSolutionExporter.ExportLists()    
 at Microsoft.SharePoint.SPSolutionExporter.GenerateSolutionFiles()    
 at Microsoft.SharePoint.SPSolutionExporter.ExportWebAsSolution()    
 at Microsoft.SharePoint.SPSolutionExporter.ExportWebToGallery(SPWeb web, String solutionFileName, String title, String description, ExportMode exportMode, Boolean includeContent, String workflowTemplateName, String destinationListUrl)    
 at Microsoft.SharePoint.SPSolutionExporter.ExportWebToGallery(SPWeb web, String solutionFileName, String title, String description, ExportMode exportMode, Boolean includeContent)    
 at Microsoft.SharePoint.ApplicationPages.SaveAsTemplatePage.BtnSaveAsTemplate_Click(Object sender, EventArgs e)    
 at System.Web.UI.WebControls.Button.OnClick(EventArgs e)    
 at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)    
 at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)    
 at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

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Jesse A. Brandenburg