New to Naim. Need Blu Ray to Nait5 help.

Hello all.  I recently purchased a used Nait5 system that consists of the pieces below.

Naim Nait5
Naim NAP200
Naim Ariva speakers w/cables
Naim Flatcap2
Naim Stageline Phono N
Naim Nat05 Tuner
Rega P3 w/Elys 1 cartridge
Rega Ear headphone amp

I'll try and keep this short and concise...

I had to order a 4pin-to-5pin to send signal from the Stageline to the Nait5.  It was missing when I bought the system. In the meantime I thought I'd set up the Nait5 with the Stageline/Rega, my Arcam BDP and speakers.  I used the RCA-to-4pin cable that was included to connect my Arcam BDP to the Nait5 via Aux 2 input.  I'm assuming this cable was used by the previous owner to send signal to the Headphone amp.  Everything was working fine. 

My 4/5pin cable from Flashback Sales arrived a few days ago.  Now I could connect the Stageline to the Flatcap2 and send signal to the Nait5.  Went home and inserted the NAP200 and Flatcap2.  Here is where I hit a snag.  When I plugged in the Stageline I started to hear both Aux1 and 2 at the same time.  I didn't want to damage anything so I unplugged the BDP right away and enjoyed some vinyl.  

What am I doing wrong?  Why can't I hear the Arcam BDP via the CD or Tuner input?  I get the feeling I connected something wrong or maybe one of the plugs should be in place?  The BDP was coming through fine when it was plugged into the AUX2 before. 

A little confused.  Again, I'm new to Naim. Appreciate the help.