I guess I'll start over... earlier I could not get midi to record, with help here on the boards I was able to remedy that, but unfortunately now I'm getting latency on the midi track, an echo of the original signal, plus I when I choose a percussion track I get percussion and piano together... I recently upgraded to Sonar X3, I never had this problem with LE.

There is a default setting in Sonar that handles turning the Midi Input Echo on/off, as you move from one midi track being in focus to a different midi track.
 
So, if I have the midi track for my piano in focus (selected), Sonar will automatically turn that track's Midi Input Echo to 'on'.  This makes it so I can hear the piano notes when I play notes on my midi controller.
 
If I then click on the midi drums track, Sonar will turn Midi Input Echo for the piano track to 'off'', and will turn it 'on' for the drums midi track.  This makes it easy to move back and forth to different midi tracks, and be able to hear only the sounds you want to hear, the ones for the midi track that is in focus.
 
You can also manually turn Midi Input Echo on/off, and I use this approach when I want to hear a layered sound, such as piano with strings, or violins with cellos or that sort of thing.
 
I would imagine you have Midi Input Echo set to 'on' for more than one midi track, and have it this way from either manually setting it, or the setting in Sonar that controls it happening automatically has been turned off.
 
To fix the problem, click Midi Input Echo to 'off' for all the midi tracks you DON'T want to hear the sounds from while playing, and make sure the Sonar setting that automatically handles it for you is set the way you really want it.
 
The setting in Sonar that controls it being handled for you is in:
 
Edit>Preferences>MIDI>Playback and Recording, and the setting is called 'Always Echo Current MIDI Track'.  Make sure this is checked if you want Sonar to handle it for you.
 
Bob Bone
 

Also, regarding the echo sound you hear when you play, this often happens when notes on a keyboard are triggered twice - once when you play them and the keyboard responds to the notes being pressed, and get triggered again by midi being echoed back from Sonar to the keyboard.
 
IF this is what might be happening, the quick fix is to go to your keyboard and find the 'functions' section of the parameters for the keyboard.  One of those functions should allow you to turn 'Local' to 'Off'.
 
Turning Local to Off tells your keyboard to stop reacting to your pressing of the keys and producing sound.  You will still be able to hear the sounds being played, because when Sonar echoes the midi note data back to your keyboard, it will react to THAT note data and produce the sound.  SO, you will end up with a single occurrence of hearing the note's sounds from your keyboard.
 
I HOPE the above matches your situation.  If not, please post back.  Also, let me know if I explained that OK, or did I just confuse you really bad.  :)
 
Bob Bone
 
 
midi cables are connecting a keyboard with its own local sounds 
 

Nomenclature.
 
I keep calling songs projects. When you press the monitor button it will send the input through the channel, whether midi or audio.
 
Then like Robert was saying there's a setting for automatically monitoring when you click on a track.
 
You can monitor many tracks and hear them all as you play to layer sounds.
 
 
 
Midi latency is a misnomer, used for audio latency. That doesn't sound like what you have if you have two of them.
 
There is midi latency but it's very minor but can cause real problems with intricate timing situations.
 
Like Robert was saying local off should fix the problem.
 
You want local off then have a midi track sent back to your keyboard so it doesn't sound until the midi messages make the round trip through the software and back to the keyboard.
 
If you're using an external keyboard, you don't say.
 
 

I just upgraded to X3 Producer and Win 7 64.  Not only do I have a HUGE latency problem, like 5 seconds before the next note can be played (the controller keyboard is 'dead' until whatever is not going on does whatever and gives up).  Also, I've noticed on TruePiano that a key just stays depressed until I stop and restart the audio engine (the panic button or whatever it is really called).  DimensionPro will play the first note sent, but just hangs on that note for a REALLY long time. 
 
PS:  I've been doing MIDI since it first came out, so if we are playing Stump the Chump, I am the chump, and I am stumped!!!!!!

Timeking
I just upgraded to X3 Producer and Win 7 64. 

I would start here!  All of your drivers will need to be updated (potentially.)  What audio interface are you using?
 
Brian

+1 to this... the upgrade to Win7 64 alone is a few days investment in getting drivers updated and stabilized. Another thing to check is hardware compatibility, some hardware (my printer and webcam) I had were not supported and had to be replaced. I made the jump from XP 32 to Win7 64, so there was a bit to bring things online correctly.

ok, got it fixed.  Uninstalled the Edirol UM2 drivers, rebooted, reinstalled, rebooted, now it works. 

Thanks for the info... I was only using one midi track, so it wasn't that... I did find the Local control on the keyboard and turned it off (don't remember turning it on and I've recorded midi before, oh well)... and that fixed the echo, but the note I hear now is the latent note, there is a delay when I play. Clicking stuff all over the place, haven't found a solution.

Have you tried shifting the driver mode (Preferences->Audio->Playback and Recording)? I have noticed latency from my MIDI controller based on the driver mode used.