Screen output without connection to user

I have a synchronous call from XI to R/3 where the called function module submits a report to get the requested data:

SUBMIT riequi20

EXPORTING LIST TO MEMORY

USING SELECTION-SET w_var_submit

WITH SELECTION-TABLE wt_selection

AND RETURN.

This works fine when I run a job where an ABAP report fires the function module, my report can pick up the result from the memory. But when I make the call from XI I get an exception saying: "Screen output without connection to user".

Would appreciate any hints that could solve this problem!

Regards,

Carl Johan Nyberg