Why can't users login in version 1.5.7 with php 4?
From Joomla! Documentation
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Because of a change made to improve security, login with is redirection will does not work for PHP 4 sites. This may also impact other areas where there is redirection, specifically polls and mailto.
To fix this:
* Add this to the end of /libraries/joomla/utilities/compat/php50x.php
if(!function_exists('stripos')) {
function stripos($haystack, $needle, $offset = 0) {
return strpos(strtolower($haystack), strtolower($needle), $offset);
}
}
* OR - Upgrade to PHP 5. PHP 4 end of life was August 8, 2008. There will not be any more PHP 4 releases, even for security. (Switching PHP versions may cause problems with some 3rd Party Plugins - be sure to test thoroughly).