Firefox 4 kills Flex application when the breakpoint is hit while debugging the flex application from Flash builder.
Firefox assumes the plugin has become unresponsive and it kills the plugin after waiting for 45 seconds for the plugin to respond.
To workaround this issue, go to about:config from the Firefox address bar.
Filter for 'dom.ipc.plugins.timeoutSecs'. Double click on the value to edit and set it to -1
