Conditional breakpoints in Unity / MonoDevelop?

I have read in the Unity documentation that conditional breakpoints are supported but I can't get it to work (also, I am new to using conditional breakpoints so maybe I'm doing something wrong). I set my breakpoints, go to the breakpoint properties, set to break on a condition only, and set the condition to be something relating to one of my game objects (i.e. this.gameObject.transform.localPosition < 50.0F). Even after doing this I hit the breakpoint every update iteration and I can see in the watch window that the condition is clearly false. Am I doing something wrong? Any suggestions? I'm using Unity3D v3.5.5f3 and MonoDevelop v2.8.2