TYPO3 Core

One more issue:
Please remove the '@' before include($path) ! This costs so much time to find the reason for a only white page instead of the EM.

mod/tools/em/index.php:
function includeEMCONF($path,$_EXTKEY) {
include($path);

if(is_array($EM_CONF[$_EXTKEY])) {
            return $this->fixEMCONF($EM_CONF[$_EXTKEY]);
        }
        return false;
    }

This would help to save a lot of hours for investigations if you end up in an error message like
http://bugs.typo3.org/view.php?id=4977
http://bugs.typo3.org/view.php?id=5873

This error is still present in today's TYPO3 4.4. trunk.
You only get a blank page and no entries in the error_log file, if you have made a syntax error, e.g.

Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING, expecting ')' in /var/www/html/trunk/typo3/ext/sr_feuser_register/ext_emconf.php on line 48

Patch set 1 of change I971da980ace41d91dc99f466f1eb137bb0a46add has been pushed to the review server.
It is available at http://review.typo3.org/2503

Patch set 2 of change I971da980ace41d91dc99f466f1eb137bb0a46add has been pushed to the review server.
It is available at http://review.typo3.org/2503

Patch set 1 of change I5dd67f1b486850ea1766dc8949b9541352632089 has been pushed to the review server.
It is available at http://review.typo3.org/2504