Please Help Error Problem

[hypertextmark]

it started happening after i installed the welcome hack on top..
i mean it was working, the hack that is. and the entire site in general next thing you know i refresh to check up on somethin
and it gave me that error

here the line from 78-79

if ($bbuserinfo['userid']!=0) {
$username=$bbuserinfo['username'];

<^>

whats weird is that i re-uploaded the original index.php file
with no edits and it gave me this

Parse error: parse error, expecting `']'' in /home/hiphopic/public_html/forums/index.php(336) : eval()'d code on line 39

and heres that line 39

$numbermembers=number_format($numbersmembers['users']);

i just dont understand.. if you can help me i'll gladly appreciate it
thanks