Pop-up dialog box when using SPROXY t.code in ECC 6.0

Hi

I have a ECC 5.0 that I am trying to connect to my XI 7.0 box for development.

When I use transaction code SPROXY in my ECC 6.0 box - I get a dialog box titled 'Enter your username and id' - with a subtitle - Resource Rep and asking me for userid and password

My SLDCHECK works fine with accesses to SLD and exchange file of my XI box from ECC 6.0. I don't have any RFC destination like ESR*PROXY . My RFC destination LCRSAPRFC tests ok.

Why am I still get this popup ? When I try executing SPROX_CHECK_IFR_ADDRESS - I get the same popup dialog box .

Correct answers will be instantly rewarded. I am really looking forward to help for this critical problem.