title: Invalid string pointer when using pd.read_clipboard()
body: <p>I have code written to read data in from the clipboard, and 90% of the time it works fine.  </p>
  
  <p>Eventually I start getting the error below, and the only thing that seems to fix it is logging out, then logging back in.  I've tried clearing my clipboard, and that does not seem to fix it.</p>
  
  <p>The data being pasted comes from another Pandas dataframe using <code>pd.DataFrame().to_clipboard(excel = True)</code></p>
  
  <p>Python 2.7.12 |Anaconda 4.1.1 (64-bit)| [MSC v.1500 64 bit (AMD64)]<br>
  Windows 7 (64-bit)</p>
  
  <blockquote>
    <p>File "C:/Users/User/home_page.py", line 20, in pasteButton<br>
         table = pd.read_clipboard(sep = '\t')<br>
     File "C:/Anaconda/lib/site-packages/pandas/io/clipboard.py", line 19, in read_clipboard<br>
    text = clipboard_get()<br>
    File "C:/Anaconda/Lib/site-packages/pandas/util/clipboard.py", line 67 in _pasteWindows<br>
    data = ctypes.c_wchar_p(handle).value<br>
    ValueError: invalid string pointer 0xFFFFFFFFDED030C0</p>
  </blockquote>
  
  <p>Does anyone have an idea as to why this is happening, and is there a workaround I can put in my code to prevent me from having to log out/in whenever this happens?</p>
  
  <p>Sample of the DF below</p>
  
  <pre><code>    No. Hats    No. Shirts  Factor
  0   0           0           2
  1   1           0           3
  2   2           0           0
  3   3           0           0
  4   4+          0           0
  5   0           1           5
  6   1           1           0
  7   2           1           2
  8   3           1           0
  9   4+          1           0
  10  0           2           0
  </code></pre>