[TYPO3-english] SQL Problem in Update wizard

[Tomas Norre Mikkelsen]

Hi,

I have a problem SQL queries and Update Wizard. I'm upgrading a solution 
to typo3lts, and got follow 3 queries, that need to be done in "compare" 
databases.

-- SQL
ALTER TABLE tx_tcdirectmail_sentlog DROP KEY authcode;
ALTER TABLE tx_tcdirectmail_sentlog ADD KEY authcode (authcode(9));
ALTER TABLE tx_skcalendar_event CHANGE cost cost tinytext default 0;

-- Result:
BLOB/TEXT column 'cost' can't have a default value

Why is it trying to change to values not allowed?

any hints and problem solving?

/Tomas