SQLSERVER 2005 EXPRESS & ATTACH MDF

I installed SBO 2005A SP:01 PL:10

My PC is a P4 2.8MHz, RAM 1,25GB, HD120GB.

My SO is Windows XP sp2.

Im running SqlServer express 2005 (9.0.3042)

Installation was ok, setup created SBO-COMMON and Demo Company.

I can also correctly create a new company database.

Problem is that: I have some customer database I need to attach.

Usually I enter in the Microsoft SQL Server Management Studio Express and I use the Attach option to attach MDF to SQL Server. SO, when I will enter in the SBO client, The company is automatically listed and I can choose it.

THis appened in the old PC. In the new PC When I attach company, company is not listed in the SBO screen.

In the Studio Express I can see the company attacched and I can query it, I correctly setup the right current server with the right session (INFOIXP03\SQLEXPRESS).

Question is that: why after the attach I cannot list my company in the SBO list?

Thank for your answers.