tablePrefix cannot used with PostgreSql database?

I use the yii 1.1.1(2010-03-14 version) and (2010-04-24 version), the database is postgresql 8.

The application is yii’s demo blog. I set the ‘tablePrefix’=> ‘tbl_’ in the config file(main.php).

run the command yiic shell blog\index.php,

in the shell, I enter the command " model * ", it runs normal as the guide description, and create successful the class User,Tag,Commment,Post,Lookup.

then, I enter the command " crud Post", the shell display the errors like " cannot find table {{post}} in the database", and exit.

I turn the database to mysql, the operation crud Post do well, and no errors.

then I try another test. go back to the Postgresql database.

I clear the ‘tablePrefix’=>‘tbl_’ in the config file.

run the shell "model *", the shell run well , and create the classes TblUser, TblComments, etc.

then enter the command "crud TblPost", the shell run well.

why the ‘tablePrefix’ cannot used in the Application with PostgreSql?