[TYPO3] Mysql error...

[Fabian König]

Hi!

Wenn I try to add or delete an item (a news or a page or a page 
content), I get this error:

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL 
result resource in /typo3_src-4.0.2/t3lib/class.t3lib_db.php on line 801

Warning: mysql_free_result(): supplied argument is not a valid MySQL 
result resource in /typo3_src-4.0.2/t3lib/class.t3lib_db.php on line 826

Warning: Cannot modify header information - headers already sent by 
(output started at /typo3_src-4.0.2/t3lib/class.t3lib_db.php:801) in 
/typo3_src-4.0.2/typo3/alt_doc.php on line 1433



Where is the problem?
I don't knwo where it comes from and my Backend-log have no information 
about any action, where the error could came from :(


Help...