DB Connect user problem

Hello guys.

I'm trying to connect BW to an SQL DB using DB Connect. What we did is create an application server mounted on Windows with the corresponding drivers. BW is on Unix with DB Oracle.

I created two source systems connecting two different DB's with SQL Server 2008. When trying to create de datasources I'm getting some kind of an error with one source system, when I click on the button "Edit datasource" I see a leyend on the bottom that says reading database or something (cause it goes too fast) and after that nothing happens. I don't see the list of fields to save the datasource, it just stays on the screen where the list of tables are.

On the other hand when I try to create the datasource with the other source system I can do it without any problem.

The only difference is that the user I'm using with the second database is an administrator full access user, but then I tried replicating this on the other DB and does not work, I also used an administrator user.

What are the permissions that the user on SQL must have to solve this kind of problems or is there any other configuration I'm missing?

Does anyone have experienced this before?