Hi guys,
-Looping: Why would that make a difference? Tried it though to no avail
 
-Input device: Positive. 4 devices midi outs into midi merger into RME Multiface MIDI in. Input set to Multiface MIDI Omni. Also tried All Devices Omni. Either should work.
 
-Event list: Nothing there as there is nothing being recorded. Well, I say nothing, as stated - the footpedal buttons are working ok.
 
Here's the specifics:
Footpedal with 10 Note buttons - recorded succesfully.
2 expression pedals on the footpedal sending controllers 1,2 / 3,4 etc all the way up to 20 depending which of the 10 note buttons was pushed last. NOT RECORDED
Keyboard keys - not recorded
Keyboard sustain pedal - not recorded
Keyboard mod and pitch - not recorded
 
So I tried removing the merger. Plugged the footpedal straight into RME MIDI In. SAME RESULTS! No expression pedal activity recorded. Only the note ons.
 
Keyboard still didn't work straight into the Multiface.
 
Once again the RME Multiface signal light is lighting up with ALL attempted commands, along with the 'MIDI Activity' light on the Windows Taskbar. And as stated, the remote control. I can set anything in Sonar to be remote controlled with any of these things that wont record, such as the keyboard, expression pedals...
 
And once again it works flawlessly in ProTools. Open up Protools, create MIDI track, press record and the event list shows note ons from the keyboard and footpedals, sustain pedal, mod wheel, pitch bend, expression pedals..
 
I appreciate the attempted help so far guys! This makes no sense at all

Have you verified you settings in Edit > Preferences > MIDI > Playback and Recording? There are checkboxes to filter the MIDI data that is recorded in SONAR.

Thanks
Thought you might be onto something there but then realised it should definitely be recording the keyboard notes if it's recording the footpedal notes. Indeed, all checked.

Not looking at Sonar right know but I believe omni shows up for each midi device you have. Are you sure on the midi track you have actually assigned the correct device as input. Also, if you have successfully inserted a soft synth in sonar you should be able to hear it when you play the keyboard midi controller when the track has focus.

Does a MIDI export of the data recorded in Protools play properly in SONAR? If not, you have an event list to work with. If it does, you might need to consider that Protools is filtering some data. Maybe MIDI-OX might help see what is going on.

You didn't mention what model your MIDI interface is. Is it connected via USB or Firewire? In Preferences-MIDI-Devices do you see the RME MIDI interface in the Input list?
 
Edit: OK. I see you said it was the Multiface. In Sonar Preferences - MIDI - Input, is it listed as the Input device? 
 
Seems to me that somehow Notes are being filtered either by the RME or by Sonar. You said you checked Preferences-MIDI Playback and Recording and all of those checkboxes were checked. So that points to the RME. I'd uninstall/reinstall the drivers for the RME box. 
 
Are you running 64-bit Sonar X2 and are the RME drivers also 64-bit? Not all 32-bit drivers work with Sonar 64-bit. Also, what version of Windows are you using? 

I can't imagine how it would be the RME seen as it's working into Protools and Sibelius etc (and probably everything else). I'll try see if the RME drivers are 32 bit and if that is conflicting with Sonar 64 bit

Check punch record settings, it could be you're trying to record in a region not selected.

Back after a week doing other things. Drivers are up to date and it's nothing to do with loop regions or anything.
Here is what I can do:
Start new project
Insert an instrument
Arm/input echo
Hit my footkeys..it plays
Hit my keyboard, it does not.
Hit record - footkeys record. Keyboard does not.
Check the input - it's set to All OMNI which includes everything which is why it's partially working.
Change it to RME Multiface MIDI incase it fixes it (that's backward logic of course as All OMNI includes this)
Try again no luck
Right click the mute button on the track, press remote control learn. See it respond to any key presses on my midi keyboard.
Try to press record again - see that the mute button is responding to my key presses and there are shaded areas in the timeline each time I press the key. Sonar is clearly seeing it.
 
As already stated this is the case whether or not I plug my midi devices into a merger box first an then into the RME single midi input. Sonar WILL NOT PLAY or record midi received from the keyboard even with just a single midi cable in the chain. That isn't the issue anyway as otherwise the keyboard would not be seen to do remote control commands.
 
I also downloaded a demo of Presonus studio one today. No issue there as in Protools as stated. Also composing in Sibelius with no issue. First thing I found in Presonus was a midi monitor which will show a 'live' event list which shows all my keying.
It is clear that Sonar would do the same were the event list live and not a list of things that actually exist in the project.
 
Hopefully this more detailed structured post helps as I can't think what else to do! Seems completely nonsensical and it's driving me nuts :(

Ok is this a recent problem or has it always been this way?
 
If it's recent, what's been changed/added/removed from your system for the time period you're talking about?
 
Have you by any chance disabled any Windows Services? I know from experience that deleting one or two seemingly innocuous looking services can really screw up your day.