Recording MIDI only on track that has focus?

I recall in older versions of Cakewalk and Sonar that I could record easily by pressing R, and not worrying about which tracks had been previously armed for record.
 
In other words, I could just select a track or clip that I wanted to record on. and not even worry about arming the track.  Pressing R would automatically arm *just* that track for recording, then would being the metronome and start recording.  When I pressed stop, I recall it would be automatically disarmed.
 
With X1 and X2, if I don't remember to disarm a track I had just been recording on, then arming a new track leaves the other track armed as well.  Pressing R adds my recorded MIDI data to both tracks.  This really slows me down, as many of my projects are predominantly MIDI, and I like to quickly move from track to track, and just press R and build my piece that way.
 
Anyone know what I'm talking about, and know how I would configure X2 to just record on the currently selected track, disarming all others?
 
Thanks.
Dave

Yeah that one has bit me a few times, forgetting to turn off record on another track, then wondering why my bass track is going crazy.

You can also just get in the habit of always hitting unarm in the mix module on the transport bar, selected track always armed would make me nervous

But I guess it's what you're used to, maybe I'll give it a try for a while and see if I mess up 

An "exclusive arm" option would be nice to.