I had this problem before in WordPress 3.0.4 when I had an older version of Post Player. It went away when I upgraded to Post Player 1.97 but the same problem is back again now that I've upgraded to 3.0.5.
I've deactivated all of my plug-ins and one by one reactivated to narrow down the perpetrator. Starting with Post Player, I activated and get this message returned:
Notice: has_cap was called with an argument that is deprecated since version 2.0! Usage of user levels by plugins and themes is deprecated. Use roles and capabilities instead. in /mnt/stor1-wc1-dfw1/380423/402464/www.acmeworx.com/web/content/wp-includes/functions.php on line 3321
When I deactivated Post Player and reactivated all the rest of my plug-ins, everything came on error free.
I know I reported this before and got a reply that has_cap is not part of the Post Player but there's no other plug-in that causes this error.
Bummer, because it seemed fine with WordPress 3.0.4