ClearUndo when _IsDirty is set to False & Show Item even if parent is collapsed.

PROMS/Volian.Controls.Library/StepRTB.cs

@@ -79,6 +79,7 @@ namespace Volian.Controls.Library
 					RTBAPI.SetLineSpacing(this, RTBAPI.ParaSpacing.PFS_EXACT);
 					//_InitializingRTB = false;
 					_IsDirty = false;
+					ClearUndo();
 				}
 			}
 		}
@@ -252,7 +253,11 @@ namespace Volian.Controls.Library
 			if (ReadOnly) return;
 			if (!_IsDirty) return;
 			bool success = _origDisplayText.Save((RichTextBox)this);
-			if (success) _IsDirty = false;
+			if (success)
+			{
+				_IsDirty = false;
+				ClearUndo();
+			}
 		}
 		#endregion
 		#region AddRtfTextAndStyles