Affected rows: 0
Warning: #1264 Out of range value adjusted for column 'deleteon' at row 1
SQL query:
UPDATE `custtable`.`custinfo` SET `deleteon` = '2011-02-29 00:00:00' WHERE `custinfo`.`custid` =105 LIMIT 1 ;

This happened after a migration to a new SQL database due to user error.  The old database server MySQL 3.23 or 4 allowed an impossible date to be entered by a user.  As we know February 29th DOES NOT exist but the database allowed the value.  MySQL 5.0 is smarter and rejected it and ended up setting a blank value for that field.  It was hard to troubleshoot at first until we actually looked at the date :)

So the solution is to use Feb-28th or March 1st since the 29th does not exist.