PHPStorm not reacting to break points - php

Question

I have recently installed PHPStorm and Xdebug in order to debug PHP scripts running on a local server. I am running Mac OS 10.8.5 and MAMP. I have been using Safari 6.2.4 as my principal browser, but the issue occurs also with Initially, I was able to get PHPStorm to stop at checkpoints I have placed, but in one script, it refused to enter a foreach() {} statement. I therefore created a small test script which contained only this statement, and tested it on its own. First PHPStorm was happy to step through each line, and then it refused to stop at any breakpoints at all, either in my small test script or in any other script.
I have spent several hours checking and rechecking the various official guides, and testing all the techniques suggested. At times, my test page will start to load, and then the progress bar in the browser will stop. I am guessing that PHPStorm is, in fact, reacting to the break point, but failing to show the debugger controls.
Here is a screenshot of this situation. Should there be another panel in the PHPStorm window, to allow me to step through the script? If so, how can I get it to appear? If not, is there any way of debugging the PHPStorm debugger?
Here are the xdebug settings in php.ini:
[xdebug]
zend_extension="/Applications/MAMP/bin/php/php5.5.3/lib/php/extensions/no-debug-non-zts-20121212/xdebug.so"
xdebug.remote_enable=1
xdebug.remote_host="localhost"
xdebug.remote_port="9000"
xdebug.profiler_enable=1
xdebug.profiler_output_dir="/Applications/MAMP/tmp"
xdebug.remote_log="/Applications/MAMP/logs/xdebug.log"
I have a Run/Debug configuration set up in PHPStorm as:
Host: web Port: 9000
Document Root: /Volumes/Sites/web
Here's the output of the xdebug.log:
Log opened at 2015-05-20 12:06:48
I: Connecting to configured address/port: localhost:9000.
I: Connected to client. :-)
-> <init xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" fileuri="file:///Volumes/Sites/web/test.php" language="PHP" protocol_version="1.0" appid="3174" idekey="1"><engine version="2.2.3"><![CDATA[Xdebug]]></engine><author><![CDATA[Derick Rethans]]></author><url><![CDATA[http://xdebug.org]]></url><copyright><![CDATA[Copyright (c) 2002-2013 by Derick Rethans]]></copyright></init>
-> <response xmlns="urn:debugger_protocol_v1" xmlns:xdebug="http://xdebug.org/dbgp/xdebug" status="stopping" reason="ok"></response>
Log closed at 2015-05-20 12:06:48
In the Run panel, I see:
/Applications/MAMP/bin/php/php5.5.3/bin/php -S jce:9000 -t /Volumes/Sites/web
[Wed May 20 08:06:48 2015] 127.0.0.1:51388 Invalid request (Malformed HTTP request)
The port number after 127.0.0.1: changes each time I refresh the browser.
PHPStorm also fails to react to breakpoints set in JavaScript files running in the browser.