I tried to save frame positions (should/does emacs itself support
this?), using ns-set-resource, and find that the updated data is not
always written to disk.  See this:
  http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/Reference/Reference.html

Here is a one line patch.

-- 
William

http://xwl.appspot.com