Problem Sql Server / PHP PDO on Debian

Hi,

We have developped a website in php / pdo on a pc. Database is sql server. It works ..

We are moving this website on a linux server (debian)

We have installed freetds to communicate with sql server but we have some problem when we execute some stored procedure :

CDbCommand::execute() failed: SQLSTATE[HY000]: General error: 102 General
SQL Server error: Check messages from the SQL Server [102] (severity 15)
[(null)]. The SQL statement executed was ...

Syntax for calling a proc is : {:returnv = CALL proc (:param1, :param2, ..)}

Thanks for your help ..