CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP

Hallo zusammen,

Ich bekomme eine Fehlermeldung beim erstellen folgender Tabelle:

CREATE TABLE ehcs_zoom_comments(
cmtid int( 11 ) NOT NULL AUTO_INCREMENT ,
imgid int( 4 ) NOT NULL default '0',
cmtname varchar( 40 ) NOT NULL default '',
cmtcontent varchar( 180 ) NOT NULL default '',
cmtdate timestamp NOT NULL default CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ,
PRIMARY KEY ( cmtid ) ,
KEY image_id( imgid ) ,
KEY id( cmtid )
);

The Error-Message is:

#1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
PRIMARY KEY

Warum erscheint dieser Fehlermeldung? Wäre dankbar für einen Tipp!

Greetings, Yves

Welche mysql Server Version wird benutzt?

http://dev.mysql.com/doc/mysql/en/create-table.html

InnoDB supports both ON DELETE and ON UPDATE actions on foreign keys as of MySQL 3.23.50 and 4.0.8, respectively. For the precise syntax, see Section 15.7.4, “FOREIGN KEY Constraints”.

For other storage engines, MySQL Server parses the FOREIGN KEY and REFERENCES syntax in CREATE TABLE statements, but without further action being taken.