First, I would test the servers session management to make sure it is saving session information corrcetly using the session test page here:
showpost.php?p=23826&postcount=2
if the session test fails, it is most likely a bad setting in the PHP.ini file for the session.save_path, your host will need to correct that.
if the session test passes, to help troubleshoot, find the following code:
if ($WAFV_Errors != "") {
PostResult($WAFV_Redirect,$WAFV_Errors,"contact");
}
and change it to:
if ($WAFV_Errors != "") {
die($WAFV_Errors."<br><pre>".var_dump($_POST)."</pre><br><pre>".var_dump($_SESSION)."</pre>");
PostResult($WAFV_Redirect,$WAFV_Errors,"contact");
}
this will write the session contents and post contents to the screen when validation fails to help find the cause of the problem.