deleting media error

When I try to delete items from the Media Library, I get this error:

Warning: implode() [function.implode]: Bad arguments. in /wp-includes/taxonomy.php on line 1621

Warning: implode() [function.implode]: Bad arguments. in /wp-includes/taxonomy.php on line 1621

Warning: Cannot modify header information - headers already sent by (output started at /wp-includes/taxonomy.php:1621) in /wp-includes/pluggable.php on line 897

I know the “headers already sent” error is well documented (http://codex.ww.wp.xz.cn/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F). However, the files mentioned are core files that I’ve not modified. Neither of them have the closing PHP delimiters, which I imagine removes the possibility of extra space after them.

Anyone get the same issue? Is it worth me scouring my theme and plugins for the “extra space” issue? Could extra space in other files create this error?

cheers,

Steve