diff -r 3e698434b990 -r f0417b6ff98a mercurial/util.py
--- a/mercurial/util.py	Wed Oct 07 14:01:20 2009 -0500
+++ b/mercurial/util.py	Thu Oct 08 00:59:46 2009 -0500
@@ -1221,6 +1221,11 @@
                 return array.array('h', arri)[1]
             except ValueError:
                 pass
+            except IOError, e: 
+                if e[0] == errno.EINVAL: 
+                    pass 
+                else: 
+                    raise 
     except ImportError:
         pass
     return 80