Fix duplicate preference window upon prefs import

swing/src/net/sf/openrocket/gui/dialogs/preferences/GeneralPreferencesPanel.java

@@ -364,9 +364,18 @@ public class GeneralPreferencesPanel extends PreferencesPanel {
 									trans.get("generalprefs.ImportWarning.msg"),
 									trans.get("generalprefs.ImportWarning.title"),
 									JOptionPane.WARNING_MESSAGE);
+
+							// Introduce a small delay before showing the PreferencesDialog
+							Timer timer = new Timer(100, new ActionListener() {  // 100ms delay
+								@Override
+								public void actionPerformed(ActionEvent arg0) {
 									PreferencesDialog.showPreferences(parent.getParentFrame());		// Refresh the preferences dialog
 								}
 							});
+							timer.setRepeats(false); // Only execute once
+							timer.start(); // Start the timer
+						}
+					});
 				}
 			}
 		});