The following problem was reported on CIX (UK) by someone who is evaluating FB. I have reproduced it in build 2004 here, but the failure is also reported not to happen on XP. Reduced to its simplest form...
On Windows 7, 64-bit, create a new project and one 'Wait for Window or Control' action. On the action dialog, just enter a target process that is known not to exist. Run the project. Press the red button 'terminate action and stop build'. FB crashes.