1. The problem is isolated to the windows platform. You are able to call multiple stored procedures on other platforms without a problem.

2. I'm not sure but it works around the bug.

3. You can always call and configure the mysqli in your code, but the ZF is based on top of PDO. So if you use Zend_Db your code will go through the PDO_Mysql adapter.

4. I don't know, but I'm sure you can search for some info on this.