Signing assemblies in VS2005 BizTalk project

The usual project properties page is not shown when I view properties for a BizTalk 2006R2 project in Visual Studio 2005. Instead I get the property dialog below. How do I get the one where you can choose to sign the assembly, the one with the tabs on the right side?

Didn't manage to fix the actual problem but signed the assembly by manually generating a kay with sn -k and assigning it to the assembly in the dialog above.