I have been having a range of problems, both with this site and another, dealing with WordPress (maybe this has something to do with version 3?)
Client called and was getting a blank page after hitting Update, Publish, Save or any other type of action in WordPress backend. Looked it up, and people were saying it has something to do with the functions.php file.. specifically removing a blank space on line 83.
I did that on client’s site, and no change. Then, I saw that one needs to make sure <?php leads the function.php file, and ?> ends it. I did that, and got more errors.
I can’t recall at one point I got this one:
Warning: Cannot modify header information – headers already sent by (output started at /home/username/public_html/wp-content/themes/default/functions.php:3) in /home/username/public_html/wp-includes/pluggable.php on line 890
I looked at that file, and it looked very strange. The first line was basically the middle of a php command. I put <?php and ?> at the front and back of that file, and it made everything look right (as far as php commands opening and closing), but I got a massive php error when trying to load the site, which was completely down at this point.
Things got much worse before they got better as I tried to make the changes recommended to functions.php and pluggable.php. I even started to file a service ticket to have everything wiped out by the host and reverted to their last backup. As a last effort, I created a new site/project in Dreamweaver, downloaded the newest version of WordPress, and put everything in that new public_html folder except the wp-content folder, updated database info in the new wp-config, and uploaded all.
I was pleasantly surprised when I refreshed the home page of the broken site, and everything was working again.