Passing a user-defined table type between SQL Server database

I have a user-defined table type in one database in SQL Server (let's call this DB1).

The definition for my type is very simple and just includes 2 columns. The script to create my type is below:

CREATE TYPE [dbo].[CustomList] AS TABLE
(
    [ID] [int] ,
    [Display] [NVARCHAR] (100)  
)

I've also run the same script on another database, so my type is on 2 databases (Let's call the 2nd database DB2).

I now call a stored procedure in DB1 from my C# app passing in the parameter for my CustomList user-defined type.

The procedure in DB1 now needs to call a procedure on DB2 passing in this CustomList.

So, the procedure in DB1 looks like this:

ALTER PROCEDURE [dbo].[selectData]
    @psCustomList CustomList ReadOnly
AS
BEGIN
    EXEC DB2.dbo.selectMoreData @psCustomList   
END

And the procedure in DB2 is like this (I've only show the parameter list as that's all that is needed):

ALTER PROCEDURE [dbo].[selectMoreData]
    @psCustomList CustomList ReadOnly
AS
BEGIN
......

When I run this I receive the following error:

Operand type clash: CustomList is incompatible with CustomList

Anybody got any ideas what I'm doing wrong?

I'm using SQL Server 2008.

Thanks in advance