Equipment: Windows 7 -64bit with 8GB Ram: Sonar X1: Tascam 144 mk II interface: Roland XP 10
 
Problem:  I open a new project. I select the midi track and arm the record button. I play a note on the synth and I can see the signal bar respond. I click on record in the tape-deck console and play notes on the synth. The time clock on the tape-deck console does not advance...i.e. not recording.
 
Here's the odd thing. About every 5th time I try this it actually does record and I can play it back through my synth???
 

Around here people call the "tape deck console" the transport module.   You don't say, but your problem only makes sense if you are recording from an external synth.  Are you using MIDI cables or USB? 
On the track you can set the MIDI input for your interface (probably should choose OMNI for this).
When recording after setting up as you describe you still need to click the "play" button on the transport module.
 

You do realize that MIDI is not sound, right? MIDI is a list of computer control commands that tell a synth (real or softsynth) what to play and when to play it. Therefore, the output of the MIDI track has to be set to some type of synth that can convert those control commands to sound. That can either be a real synth connected to your computer via USB or a MIDI cable, or a softsynth that you insert into your project using Insert-Softsynth. If using an external synth, it has to be set to receive the MIDI data on the same channel that the computer is sending it on. Usually you will want to put the synth in General MIDI mode and then it can play multiple voices at a time. There is much more on this at this link: http://www.cakewalk.com/support/kb/reader.aspx/2007013075

To answer a few questions:
Yes I realise midi is bit information and not actual music. In my posting I mention the Roland XP 10 as my keyboard.
I input the data via midi from the xp 10 to the Tascam 144MkII interface (which is external to my computer and connected by USB). The midi channel is fine and the interface has been selected for both input and output. In this way after I record the midi data I can dump it back out to my synth which is connected to amplification (in order to hear sound).
 
From what I can gather from one response...after I have armed (R for record) on the midi track, I must press R on the transport module and then the PLAY button after that in order for it to proceed recording??
 
 
 

Detailed steps on the MIDI recording process from  http://www.cakewalk.com/Documentation/default.aspx?Doc=SONAR%20X2&Lang=EN&Req=Tutorial4.3.html#1156321
 
Click the track's Record Enable button . This enables recording on the track. Now, click the Record button in the Control Bar’s Transport module. The Now Time cursor starts to roll. Play some notes and click the Stop button when you're done. You have just recorded your first MIDI performance through a software instrument. Press the Play button to hear it play back.
 

Scook:
As I said above, I have done exactly what you have suggested but the Now Time Cursor doesn't move.
However every 5th time or so  it does move and I get the midi to record (and playback) . Why the sporadic behaviour??

georgesmith707
Scook:
As I said above, I have done exactly what you have suggested but the Now Time Cursor doesn't move.
However every 5th time or so  it does move and I get the midi to record (and playback) . Why the sporadic behaviour??

Could it be that your mouse is defective.

OK ...I made a discovery. I have no idea why this happens but...
Opened a new project
If I record an audio track FIRST, the midi recording works fine.
If I try to record midi first, the time cursor doesn't move???
 
go figure??  any ideas?

georgesmith707
OK ...I made a discovery. I have no idea why this happens but...
Opened a new project
If I record an audio track FIRST, the midi recording works fine.
If I try to record midi first, the time cursor doesn't move???

go figure??  any ideas?

That shouldn't be necessary to record audio first. My first thought when reading this post was that the MIDI engine was stopping, and needed to be re-clicked.
 
Up in the Control/Transport bar [Press 'C' to toggle on & off - *maybe for X2 only*], there should be Audio and MIDI 'engine' buttons. Locate those and see how they behave. They normally stay on, unless there is something adverse happening.
 
Based on past experiences, this would be my first idea. 

I have noticed as well that if I do alot of MIDI data editing and go and use the transports (either key bindings or icons on the screen).  The playback and stop and recording, etc, all act very sluggish.....
 
The workaround is to do a save to the project and that frees up the sluggishness... this and other things, leads me to my theory that the undo buffer management with lots of data in the buffers, somehow effects the performance of the SONAR and that the SAVE function then cleans up.  This is not the only performance issue caused by the large edits sessions for me but the SAVE workaround always works.
 
Jim