Problem with midi keyboards and signal

If I need to put this in a different forum let me know... sorry if it shouldn't be here....
I’m having a problem with my midi keyboards… When I open a project and insert a synth the small icon with the two lights appears in my systray. (as it should) The left light stays on and I can see a partial signal being sent to that track even though I'm not touching a key…(as it shouldn’t) This causes half of my track pane to be shaded as I record… I also notice that when I use my sustain pedal it doesn’t always sustain…(I have tried 3 different pedals so I know it’s not the pedal) Now my two midi keyboards are connected directly to USB ports on my computer, (not a hub)…And I’ll add I have bought new chords, used old chords, swapped out chords thinking that maybe it was a bad usb cable…  I have tried switching the chords to different ports but I still have the problem… My Casio electric piano is connected to my interface via a midi cable and I have no problems with a partial signal being sent from that, (although I do have problems with sustain at times) I usually just leave the sustain pedal down rather than use it the way it’s supposed to be used… I never really did any type of instrument setup in my Sonar other than plug them in and my computer recognized them as did my software… Did I miss a setup dealio? Is there a ghost in the machine? My computer is fairly new and dedicated strictly to record… I have a quad in it and plenty of RAM and HD space… Any ideas?  

Evenin' Beegs....  Haven't had to lean your way in awhile... Hope you're well... The problem is data being sent to the computer always... You can see it in the icon with the left light stuck on... and I'm not touching any keys... It's not recording anything although once I arm the track it will record whatever synth I've chosen... I can only call it a partial signal as I don't know how else to explain it except 'only' the left lite is stuck on and if I look at the meter on the track of whatever synth I inserted I can see it reading a fluctuating signal. Usually when you hit the keys on the midi controller both lites come on with each hit of the keys...It's got to be part of the synth program.. In my Korg midi controllers they are usb cabled to my usb ports on my puter.... With my Casio piano I am using one midi cable from the 'out' on the keyboard to the 'in' on my interface...
Is there an 'Instrument setup' I need to do? Like I said earlier I just plugged them in and made sure I assigned my ins and outs to whichever synth I had chosen... and they worked but I know they're not working correctly...
Thanks Beegs

clarification - swap the ins and outs of the midi cable on ONE side - either the keyboard side or the interface side - not both.

If there's a "partial signal" coming from the keyboard..... what happens when you arm the midi track and start the recording while NOT pressing any keys?

What I'm asking is ...do you see anything being recorded into the track during that record session?

Seems to me if midi data is coming out of the keyboard, it would be recorded and become visible in the track.  I see the notes as horizontal lines in the track and the expression pedal data is recorded and shown on the bottom of the track...... are you seeing anything in that track after you stop the recording?

have you tried swapping the cables yet? 

another thing to try for troubleshooting is to disconnect the keyboards one at a time.  especially the one with MIDI cables.  this really sounds like a midi feedback loop;