[Plugin: Developer Formatter] Getting Use of undefined constant GESHI_CAPS_NO_CHANGE and several fat

Thanks for a nice plugin, on the service it works, but in my Apache logs, two annoying things are happening:

1. all the geshi language php scripts are apparently somehow linked from the pages, google crawlers find them and, though the response is empty, index them. How do I prevent that from happening?

2. I receive many errors in the logs, here’re some of them:

Use of undefined constant GESHI_CAPS_NO_CHANGE – assumed ‘GESHI_CAPS_NO_CHANGE’
Use of undefined constant GESHI_NUMBER_INT_BASIC – assumed ‘GESHI_NUMBER_INT_BASIC’
PHP Fatal error: Call to undefined function add_action()
PHP Fatal error: Call to undefined function plugin_basename()
PHP Fatal error: require_once() [function.require]: Failed opening required ‘DEVFMT_PATHgeshi\\geshi.php’ (include_path=’.;C:\\php5\\pear’)

all in php-brief.php, but also in many others, matlab.php, apache.php, io.php, devformatter.php and devcommon.php etc. Any idea how to resolve? I understand PHP but wouldn’t really want to have to dive into it.

Thanks in advance if you could shed some light on this