title: NSString - doubleValue is returning NaN from a viable NSString
body: <p>Ok, so I am pulling an NSString from and NSMutableArray and storing it in an NSString:</p>
  
  <pre><code>entry = [NSString stringWithString:[array objectAtIndex:row]];
  </code></pre>
  
  <p>This is wrapped inside of a couple different for-loops. I then convert it to a doubleValue and store it in a number but apparently [entry doubleValue] only returns a NaN instead of a number.  I threw in an NSLog for 'entry' and '[entry doubleValue]'.  EVERY time I run this I get the same results:</p>
  
  <pre><code>entry: 22.414 value: nan
  </code></pre>
  
  <p>Any ideas? thanks!</p>