Apple Logic Pro /LogicExpress Discussion

Hi All,
   Hoping someone can help with this as searches have not helped this 
far.  OK,  so I create a track for a virtual instrument (Stylus/Virus 
TI)in Logic. No problem there everything works fine.  Next, I add 
another track (new instrument/next midi channel) for the same 
instrument on the next midi channel.  Now,  I can play the instrument 
from this next midi channel, BUT, if I change the volume fader or want 
to mute just one channel,  EVERY channels volume changes and/or all 
channels are muted if I hit mute.  I'm sure this HAS to be something 
simple that I've been overlooking but I've not been able to figure it 
out.  
    Any help will be appreciated!    Thanks in advance,  Randy