TYPO3 Core

With the new 4.0RC1 I get a lot of problems by not be able to change tables.

I am using IIS 6.0 and mySQL 4.1.12 under Server 2003

Below the commands which are not working:

ALTER TABLE be_users CHANGE lang lang char(4) default '';
Current value: varchar(4) default ''
ALTER TABLE sys_refindex CHANGE ref_string ref_string text NOT NULL;
Current value: varchar(200) default ''
ALTER TABLE static_countries CHANGE cn_iso_2 cn_iso_2 char(4) default '';
Current value: varchar(4) default ''
ALTER TABLE static_countries CHANGE cn_iso_3 cn_iso_3 char(6) default '';
Current value: varchar(6) default ''
ALTER TABLE static_countries CHANGE cn_tldomain cn_tldomain char(4) default '';
Current value: varchar(4) default ''
ALTER TABLE static_countries CHANGE cn_currency_iso_3 cn_currency_iso_3 char(6) default '';
Current value: varchar(6) default ''
ALTER TABLE static_country_zones CHANGE zn_country_iso_2 zn_country_iso_2 char(4) default '';
Current value: varchar(4) default ''
ALTER TABLE static_country_zones CHANGE zn_country_iso_3 zn_country_iso_3 char(6) default '';
Current value: varchar(6) default ''
ALTER TABLE static_currencies CHANGE cu_iso_3 cu_iso_3 char(6) default '';
Current value: varchar(6) default ''
ALTER TABLE static_currencies CHANGE cu_thousands_point cu_thousands_point char(2) default '';
Current value: varchar(2) default ''
ALTER TABLE static_currencies CHANGE cu_decimal_point cu_decimal_point char(2) default '';
Current value: varchar(2) default ''
ALTER TABLE static_languages CHANGE lg_iso_2 lg_iso_2 char(4) default '';
Current value: varchar(4) default ''
ALTER TABLE static_languages CHANGE lg_typo3 lg_typo3 char(4) default '';
Current value: varchar(4) default ''

Is this a problem of the mySQL-Version?
Which version is recommed to use?
Can this create some problems with typo3?

(issue imported from #M2891)