Thanks for your answers. When I stepped thru I found that my validation rules weren't checking for the deleted status on the rowset. This is the code actually throwing the exeception:

this.ValidateName(dr["cname1"].ToString());
System.Data.DeletedRowInaccessibleException was unhandled
  Message="Deleted row information cannot be accessed through the row."
  Source="System.Data"
  StackTrace:
       at System.Data.DataRow.GetDefaultRecord()
       at System.Data.DataRow.get_Item(String columnName)
       at Mainstreet.GlasAve.BusinessObjects.CustomerRules.CheckRulesHook(DataSet ds, String tableName) in D:\dotnet\glasave8\Glas-Avenue8\MM Business Object Library1\CustomerRules.cs:line 36
       at OakLeaf.MM.Main.Business.mmBusinessRule.CheckRules(DataSet ds, String tableName, Boolean useErrorProvider)
       at OakLeaf.MM.Main.Business.mmBusinessObject.CheckRules(mmBusinessObject businessObject, DataSet ds, String tableName)
       at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(DataSet ds, String tableName, String databaseKey, IDbDataAdapter dbAdapter)
       at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(DataSet ds, String tableName, String databaseKey)
       at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(DataSet ds, String tableName)
       at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(String tableName)
       at OakLeaf.MM.Main.Business.mmBusinessObject.SaveRow()
       at Mainstreet.GlasAve.BusinessObjects.test.customer_test_CustomerDelete() in D:\dotnet\glasave8\Glas-Avenue8\POS_test\test.cs:line 31
       at Mainstreet.GlasAve.BusinessObjects.test.Main(String[] args) in D:\dotnet\glasave8\Glas-Avenue8\POS_test\test.cs:line 15
       at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()