Hi Vitaly,
When you perform your FP_CHECK_DESTINATION_SERVICE check, test with and without "With Destination Service" set.
Also check your default trace file on the J2EE when you perform the check as this will give you additional info.
Another thing I would do is that you try and logon to your ABAP stack with users ADSUSER/ADS_AGENT (set them temporarily to DIALOG) in order to be 100% sure that the passwords you have configured are correct.
Final thing I would do is to regenerate the roles given to ADSUSER/ADS_AGENT on the ABAP side and make sure the traffic light is green as well as the "user comparison" traffic light is green.
You'll laugh about this by the end of the day :-)
Kindest Regards,
Amerjit