Warning: array_keys()
 

My site was hacked by some jerk named "Top Sat 13" and I had to have my database restored to a week-old version.

Now when I go to my forums* I get the following at the top of every page and it won''t let me login
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Code:
Warning: array_keys(): The first argument should be an array in [path]/includes/functions.php on line 4227

Warning: Invalid argument supplied for foreach() in [path]/includes/functions.php on line 4227

Warning: Invalid argument supplied for foreach() in [path]/includes/functions.php on line 3414
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it also gives me the following error on each page.

Code:
Unable to add cookies* header already sent.
File: /path/to/my/files/forums/includes/class_core.php
Line: 3277
Since getting these messages* I re-downloaded v3.8.3 from the member site and re-uploaded all new files. I still get the same message.

Ideas?