Unable to install

You need PHP5.

For PHP4:

Search in dbfm.module and dbfmgreybox.module for the line with the function stripos().
Insert following code (in the line befor stripos):

if (!function_exists('stripos')) {
function stripos($string,$word){
$retval = false;
for($i=0;$i<=strlen($string);$i++) {
if (strtolower(substr($string,$i,strlen($word))) == strtolower($word)) {
$retval = true;
}
}
return $retval;
}
}