The Debugger no longer stops at my breakpoints, and the breakpoint icons are now gray instead of green! What has happened?
Most likely, you've pressed a button and don't remember it. To correct the problem, open the Debugger, select the 'Breakpoints' tab, and then make sure that the 'Global Enable Breakpoints' (third button on the toolbar) is selected. This button is a quick way to enable/disable *all* your breakpoints, resulting in the seemingly bad behavior.