--- netchoosedialog.cpp.old	2007-05-13 22:30:12.000000000 +0100
+++ netchoosedialog.cpp	2007-05-13 22:30:51.000000000 +0100
@@ -102,7 +102,9 @@
 
 void NetChooseDialog::OK() {
   // save SMILES string of selected item
-  fn = lv->selectedItem()->text(4);
-  fn.replace("\"", "");  // strip quotes
-  accept();
+  if(lv->selectedItem() != 0){
+    fn = lv->selectedItem()->text(4);
+    fn.replace("\"", "");  // strip quotes
+    accept();
+  }
 }