It appears that you cannot have multiple devices or device sets initialized from within the same process. Looks like we'll have to work around it...
From the help:
The CreateEx (and Create) calls will modify the security DACL on the process handle in the client process. Because of this, any other modification of the process handle must be serialized with invocation of CreateEx. CreateEx will serialize with other calls to CreateEx, but is unable to serialize with external processing. Access is granted to the account running the SQL Server service.
It appears that you cannot have multiple devices or device sets initialized from within the same process. Looks like we'll have to work around it...
From the help:
The CreateEx (and Create) calls will modify the security DACL on the process handle in the client process. Because of this, any other modification of the process handle must be serialized with invocation of CreateEx. CreateEx will serialize with other calls to CreateEx, but is unable to serialize with external processing. Access is granted to the account running the SQL Server service.