user mapping problem? [connecting EP to BW]

Hello,

I am trying to put an SAP BW report on a Portal page...

The connection test (run from system landscape) to the BW

system fails.

At the same time I can preview the iView based on this

BW system, the only thing I have to do before the iView

is displayed is to enter BW user name / password (login

widow pops up).

The iView is also displayed on the portal page (when

logged as an end-user). But again, the user has

to enter the user name / password.

I have defined user mappings for EP users (i.e. for

every EP user I have defined a mapping to a BW user).

What can I do so that the EP end-users don't have

to enter the BW user id / password when they display

the page with the iView? Is this the user mapping

problem, SSO problem, or maybe connectivity problem?

SAP EP version is 6.0 SP 9.

Any help highly appreciated.

Greetings,

Tomek.