no output using x64 compilation but ok on win32 ??

I have recently reloaded silverfrost but now find I am having a problem printing to a file. See simple program below. It works when compiled under win32. The program runs when compiled under x64 but nothing is printed to file. What am I missing? Appreciate any help.

  Program Simple_test
  open(10,file='test.out')
  write(10,20)

20 format('this is a test') stop end

It works OK for me.

I am using the latest clearwin64.dll and that might make a difference.

Try calling close(10) before exiting.