diff -ru ../scidcvs.git/tcl/end.tcl ./tcl/end.tcl
--- ../scidcvs.git/tcl/end.tcl	2009-07-17 11:40:23.000000000 -0500
+++ ./tcl/end.tcl	2009-07-24 03:42:37.000000000 -0500
@@ -1450,6 +1450,11 @@
 
 proc getCommandLineOptions {} {
   global argc argv windowsOS loadAtStart
+  if { $::macOS && ([string first "-psn" [lindex $argv 0]] == 0)} {
+    # Remove Process Serial Number from argument list:
+    set argv [lrange $argv 1 end]
+    incr argc -1
+  }
   while {$argc > 0} {
     set arg [lindex $argv 0]
     set firstChar [string index $arg 0]