Description of problem:
vim has a python interface that allows programmatic access to the current editor
buffer. 
:py vim.current.buffer[:] = [ 'test' ]
Used to be able to reset the buffer contents to only one line 'test' in fc6,
now it appends the line 'test'.

Version-Release number of selected component (if applicable):
vim-enhanced-7.0.224-3.fc7

How reproducible:
always

Steps to Reproduce:
1. vim
2. :py import vim
3. :py vim.current.buffer[:] = [ 'test' ]
4. :py vim.current.buffer[:] = [ 'test' ]
  
Actual results:
test
test

Expected results:
test

Additional info: