diff -r 9254970bc67e Lib/idlelib/PyShell.py
--- Lib/idlelib/PyShell.py	Thu Jan 13 00:39:31 2011 +0100
+++ Lib/idlelib/PyShell.py	Fri Jan 14 06:30:19 2011 -0800
@@ -1417,6 +1417,13 @@
             shell.interp.prepend_syspath(script)
             shell.interp.execfile(script)
 
+    # Check for problematic OS X Tk versions and print a warning message
+    # in the IDLE shell window; this is less intrusive than always opening
+    # a separate window.
+    tkversionwarning = macosxSupport.tkVersionWarning(root)
+    if tkversionwarning:
+        shell.interp.runcommand(''.join(("print('", tkversionwarning, "')")))
+
     root.mainloop()
     root.destroy()
 
diff -r 9254970bc67e Lib/idlelib/macosxSupport.py
--- Lib/idlelib/macosxSupport.py	Thu Jan 13 00:39:31 2011 +0100
+++ Lib/idlelib/macosxSupport.py	Fri Jan 14 06:30:19 2011 -0800
@@ -34,6 +34,23 @@
                          'AppKit' not in root.tk.call('winfo', 'server', '.'))
     return _carbonaquatk
 
+def tkVersionWarning(root):
+    """
+    Returns a string warning message if the Tk version in use appears to
+    be one known to cause problems with IDLE.  The Apple Cocoa-based Tk 8.5
+    that was shipped with Mac OS X 10.6.
+    """
+    
+    if (runningAsOSXApp() and
+            ('AppKit' in root.tk.call('winfo', 'server', '.')) and
+            (root.tk.call('info', 'patchlevel') == '8.5.7') ):
+        return (r"WARNING: The version of Tcl/Tk (8.5.7) in use may"
+                r" be unstable.\n"
+                r"Visit http://www.python.org/download/mac/tcltk/"
+                r" for current information.")
+    else:
+        return False
+
 def addOpenEventSupport(root, flist):
     """
     This ensures that the application will respont to open AppleEvents, which
diff -r 9254970bc67e Mac/BuildScript/resources/ReadMe.txt
--- Mac/BuildScript/resources/ReadMe.txt	Thu Jan 13 00:39:31 2011 +0100
+++ Mac/BuildScript/resources/ReadMe.txt	Fri Jan 14 06:30:19 2011 -0800
@@ -1,29 +1,36 @@
 This package will install Python $FULL_VERSION for Mac OS X
-$MACOSX_DEPLOYMENT_TARGET for the following 
-architecture(s): $ARCHITECTURES.
+$MACOSX_DEPLOYMENT_TARGET for the following architecture(s):
+$ARCHITECTURES.
 
-Separate installers are available for older versions
-of Mac OS X, see the homepage, below.
+Installation requires approximately $INSTALL_SIZE MB of disk space,
+ignore the message that it will take zero bytes.
 
-Installation requires approximately $INSTALL_SIZE MB of disk
-space, ignore the message that it will take zero bytes.
+You must install onto your current boot disk, even though the
+installer does not enforce this, otherwise things will not work.
 
-You must install onto your current boot disk, even
-though the installer does not enforce this, otherwise
-things will not work.
+Python consists of the Python programming language interpreter, plus
+a set of programs to allow easy access to it for Mac users including
+an integrated development environment, IDLE, plus a set of pre-built
+extension modules that open up specific Macintosh technologies to
+Python programs.
 
-Python consists of the Python programming language
-interpreter, plus a set of programs to allow easy
-access to it for Mac users including an integrated development
-environment, IDLE, plus a set of pre-built extension modules
-that open up specific Macintosh technologies to Python programs.
+                    **** IMPORTANT ****
+                    
+Before using IDLE or other programs using the tkinter graphical user
+interface toolkit, visit http://www.python.org/download/mac/tcltk/
+for current information about supported and recommended versions
+of Tcl/Tk for this version of Python and Mac OS X.
 
-The installer puts the applications in "Python $VERSION" 
-in your Applications folder, and the underlying machinery in
-$PYTHONFRAMEWORKINSTALLDIR. It can optionally place
-links to the command-line tools in /usr/local as well,
-by default you have to add the "bin" directory inside
-the framework to you shell's search path.
+                    *******************
+
+The installer puts applications, an "Update Shell Profile" command,
+and an Extras folder containing demo programs and tools into the
+"Python $VERSION" subfolder of the system Applications folder,
+and puts the underlying machinery into the folder
+$PYTHONFRAMEWORKINSTALLDIR. It can
+optionally place links to the command-line tools in /usr/local/bin as
+well. Double-click on the "Update Shell Profile" command to add the
+"bin" directory inside the framework to your shell's search path.
 
 More information on Python in general can be found at
 http://www.python.org.
diff -r 9254970bc67e Mac/BuildScript/resources/Welcome.rtf
--- Mac/BuildScript/resources/Welcome.rtf	Thu Jan 13 00:39:31 2011 +0100
+++ Mac/BuildScript/resources/Welcome.rtf	Fri Jan 14 06:30:19 2011 -0800
@@ -1,19 +1,35 @@
-{\rtf1\ansi\ansicpg1252\cocoartf949\cocoasubrtf430
+{\rtf1\ansi\ansicpg1252\cocoartf1038\cocoasubrtf350
 {\fonttbl\f0\fswiss\fcharset0 Helvetica;}
 {\colortbl;\red255\green255\blue255;}
-\paperw11900\paperh16840\margl1440\margr1440\vieww9920\viewh10660\viewkind0
+\paperw11904\paperh16836\margl1440\margr1440\vieww9640\viewh10620\viewkind0
 \pard\tx720\tx1440\tx2160\tx2880\tx3600\tx4320\tx5040\tx5760\tx6480\tx7200\tx7920\tx8640\ql\qnatural
 
 \f0\fs24 \cf0 This package will install 
-\b MacPython $FULL_VERSION
+\b Python $FULL_VERSION
 \b0  for 
 \b Mac OS X $MACOSX_DEPLOYMENT_TARGET
 \b0 .\
 \
-MacPython consists of the Python programming language interpreter, plus a set of programs to allow easy access to it for Mac users including an integrated development environment \b IDLE\b0  plus a set of pre-built extension modules that open up specific Macintosh technologies to Python programs.\
+
+\b Python for Mac OS X
+\b0  consists of the Python programming language interpreter, plus a set of programs to allow easy access to it for Mac OS X users including an integrated development environment 
+\b IDLE
+\b0  and a set of pre-built extension modules that open up specific Macintosh technologies to Python programs.\
 \
-See the ReadMe file for more information.\
+See the ReadMe file and the Python documentation for more information.\
 \
 
 \b NOTE: 
-\b0 This package will by default not update your shell profile and will also not install files in /usr/local.  Double-click \b Update Shell Profile\b0  at any time to make $FULL_VERSION the default Python.}
+\b0 This package will by default not update your shell profile and will also not install files in /usr/local.  Double-click 
+\b Update Shell Profile
+\b0  at any time to make $FULL_VERSION the default Python.\
+\
+
+\b IMPORTANT:
+\b0  
+\b IDLE
+\b0  and other programs using the 
+\b tkinter
+\b0  graphical user interface toolkit require specific versions of the 
+\b Tcl/Tk
+\b0  platform independent windowing toolkit.  Visit {\field{\*\fldinst{HYPERLINK "http://www.python.org/download/mac/tcltk/"}}{\fldrslt http://www.python.org/download/mac/tcltk/}} for current information on supported and recommended versions of Tcl/Tk for this version of Python and Mac OS X.}
\ No newline at end of file