Any clue why Im getting these?

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /hermes/bosweb/web211/b2114/ipw.poly71co/public_html/alumni/includes/auth.php:755) in /hermes/bosweb/web211/b2114/ipw.poly71co/public_html/alumni/includes/auth.php on line 367

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /hermes/bosweb/web211/b2114/ipw.poly71co/public_html/alumni/includes/auth.php:755) in /hermes/bosweb/web211/b2114/ipw.poly71co/public_html/alumni/includes/auth.php on line 367

What version of PHP are you using?

Php 5

On what page do you get this error?

All of them, the file name being loaded in the error never changes from auth.php:755.

I had made the change to code earlier to:
global $main_template, $error_msg, $rand_seed, $seed, $auth;

as someone else was having the same error I was at that time. It worked well, this started well after that change.

Do you have a link where I can see this?

Yup...

Poly High Class of 71 and Friends (http://www.poly71.com/alumni/index.php)

Where did you add the banner? I think you edited something here that is either pushing text before the user is being processed, or throwing an error somewhere.

If you are unsure, could you please reupload all of the original files (including templates) and see if the error persists.

As I recall the banner simply replaced the bgheader.gif file. I re-uploaded a fresh copy, that errors gone, but now I get this one when clicking register.

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /hermes/bosweb/web211/b2114/ipw.poly71co/public_html/alumni/register.php on line 136

Warning: array_rand() [function.array-rand]: First argument has to be an array in /hermes/bosweb/web211/b2114/ipw.poly71co/public_html/alumni/register.php on line 140

Can't register!! - World Wide Creations Forum (http://www.worldwidecreations.com/forums/showthread.php?t=2695)

Ok that worked, now when I click on admin I get...

The server encountered an unexpected condition which prevented it from fulfilling the request.The script had an error or it did not produce any output. If there was an error, you should be able to see it in the error log.

Nothing in the log.