Can't Install/Edit Payment Modules

I recently moved my Zen Cart site to a new host. I have everything working fine, except I am unable to take my Authorize.net AIM payment module out of **TESTING **status because the screen to edit the payment module is not appearing. When I click the INFO/EDIT button on the screen, it just refreshes the screen, but the sidebar does not appear.
Screen shot here:
http://dl.dropbox.com/u/3531062/modules.png

Please help me figure out why I can not edit the settings for my payment module.

Thank you.

Compare the relevant admin files to your local file system backup. There may be a file missing or corrupt on your new server.

If it worked before the move then there should be no reason why the module would not work now - provided the transfer has been done "by the book"

Look in your cache directory to see if there's an error log.

Thanks.
here's the only error that I see in the logs:

[20-Aug-2011 09:39:57] PHP Parse error: syntax error, unexpected $end in /home/content/41/8241841/html/includes/modules/payment/paypalwpp.php on line 1542

I copied a fresh paypalwpp.php file from Zen Cart and it works now!
Thanks for leading me in the right direction!

That would be your answer then. Load a fresh copy of this file onto your site.