Hi Jack,
From 9.0 PL09, only CR 2013 for B1 is supported. This is because there is a conflict on BOE Runtime which is automatically installed when Integration Package is installed in this one or higher patch.
If you insists in using CR 2011, you need to manually install BOE runtime to a low version.
However I still strongly recommend you use CR 2013, otherwise SAP support will suggest you to use CR 2013 if you encounter any problem.
Thanks,
Maggie