NSLogWriter ArgumentOutOfRangeException
===

As you can see in the attached screenshot, I am checking the length of sb and if it's not 0, it will execute the Replace command.

However, somehow the Length is zero and it is executing the Replace command and throwing an exceptiong.  But there is content in '_str', so I don't understand how the length could be zero...

Is this a bug in StringBuilder?

![enter image description here][1]


  [1]: http://i.stack.imgur.com/13P8k.png