Index: library/nx/nx.tcl
===================================================================
diff -u -r3dbd5a14272ab193bb0769a28017ced9e0d80d76 -rbb688b8cd74e308d9df7cc21e29ca9bed50e3fd2
--- library/nx/nx.tcl	(.../nx.tcl)	(revision 3dbd5a14272ab193bb0769a28017ced9e0d80d76)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision bb688b8cd74e308d9df7cc21e29ca9bed50e3fd2)
@@ -2191,7 +2191,7 @@
   }
 
   ::nx::VariableSlot public method value=delete {-nocomplain:switch obj prop value} {
-    set old [::nsf::var::set $obj $prop]
+    set old [::nsf::var::get $obj $prop]
     set p [lsearch -glob $old $value]
     if {$p>-1} {::nsf::var::set $obj $prop [lreplace $old $p $p]} else {
       return -code error "$value is not a $prop of $obj (valid are: $old)"