[TYPO3] problem with installing RealURL extention

[whytone]

During installation of extention Typo3 has shown a mistake Table 'store_typodb.cache_hash' doesn't exist. On the next step of installation, it didn't finish due to 

Table 'store_typodb.cache_hash' doesn't existERROR: Query could not be parsed: "SQL engine parse ERROR: No ) parenthesis in list: near "(220),expire) ) "". Query: "CREATE TABLE tx_realurl_uniqalias ( uid int(11) NOT NULL auto_increment, tstamp int(11) NOT NULL default '0', tablename varchar(50) NOT NULL default '', field_alias varchar(30) NOT NULL default '', field_id varchar(30) NOT NULL default '', value_alias varchar(255) NOT NULL default '', value_id int(11) NOT NULL default '0', lang int(11) NOT NULL default '0', expire int(11) NOT NULL default '0', PRIMARY KEY (uid), KEY tablename (tablename), KEY bk_realurl01 (field_alias,field_id,value_id,lang,expire), KEY bk_realurl02 (tablename,field_alias,field_id,value_alias(220),expire) );"

Give please an advice how to install this extention, whether and how I need to install 'store_typodb.cache_hash' table, cause our web-site needs Clean URLs.

Thanks in advance