Michelle911
... The problem is when attempting both keyboards at once.  Sonar, in the Preferences window, only sees one keyboard at a time. And is seems a random chance as to which one decides to show up.  So it's not a midi configuration thing or getting them to respond to midi messages together. 
 
Oh, and it's not just Sonar, but Ignite, MidiOx (a little free midi monitor I found for testing) and every other music program that works with midi devices.... but Device Manager in Windows sees them both.  So I'm at a total loss here.  Especially since I have other midi gear and those are all available.
 
Thanks for the help btw :)

This might help, from our own Craig Anderton, Esq.   Solving The Windows MIDI Port Problem.  It's worth a look.  I also have a lot - and I mean A LOT - of integrated MIDI hardware in my system.  It all requires systematic maintenance, on multiple levels.

b rock
This might help, from our own Craig Anderton, Esq.   Solving The Windows MIDI Port Problem.  It's worth a look.  I also have a lot - and I mean A LOT - of integrated MIDI hardware in my system.  It all requires systematic maintenance, on multiple levels.

Thanks for that b rock.  I had a go at it, found some extra midi devices alright, uninstalled them...  unfortunately it didn't make a difference.

Did you restart?

yeah, I reset. double checked devices and made sure everything was good. I've tried reinstalling drivers and keyboards both, in different orders even...  tried the keyboards on two different hubs and on my motherboards built in ports... I tried different cables, short ones and long ones - with and without ferite beads. I've checked my USB drivers, unplugged all other midi gear and tried with just keyboards alone...  I'm pretty ok with computers, and know my way around...  I've tried a million things in the last week or so since I got my new Air49.  Really wanted to get this working.... but I'm at a loss now.
 
 

 
You may already have done this, but I think you should try isolate just where things go wrong on your system, as others seem to not have problems.
 
Have you tried the most basic setup possible, just one keyboard that works properly, no other gear or software.
 
Then the other keyboard by itself (just to make sure both keyboards are ok).
 
Then, when you add a second keyboard to this most basic setup, what happens ?
 

Hi Paul, thanks for trying to help, I really need it. lol
 
I have tried exactly what you suggest, I tested both keyboards separately (my Axiom25 was first and I used it for some time before getting my Axiom Air49), but yeah, both keyboards work beautifully with AND without my other midi gear plugged in. 
 
Dan from M-Audio (he's an employee) say this:
 

Dan
Had you installed the drivers for both controllers? Even though the Axiom series is class-compliant, Windows does require drivers for some functions. Using multiple units in tandem is one of them.

 
so to your last question
 

Paul P
Then, when you add a second keyboard to this most basic setup, what happens ?

I add the second keyboard and it shows up in Device Manager, as it should with no errors.  I then proceed to load my Daw (I have Air Ignite too)  or Midi-Ox, or anything that uses midi devices I go the Preferences, or midi device setup and the keyboard I've added is simply not listed.
 
Dan doesn't seem to answer posts everyday...  so currently waiting on a new reply there.
 
This is a link to that post.

I backed out of M-Audio gear last year. I own both an M-Audio Ozone, and M-Audio Keystation 61es, and used the Ozone for a long time before replacing it (the Keystation is rarely used). The issue I had was the drivers for the Ozone conflicted with the drivers for my Focusrite Saffire, very similar to what ASIO4ALL does (the Ozone drivers took precedence and interfered with others), forcing me to uninstall the Ozone drivers completely and route it via MIDI cables to the Saffire. I also found during that time that the Ozone was not class compliant (i.e., without drivers loaded, it did not work via USB without drivers loaded, even powered via a power supply). I noticed that there are two sets of software drivers to load and that two replies to you were deleted from the thread you linked, so I have a concern that those two sets may be conflicting as you have seen this behavior on all software tried so far.
 
A couple things that did come to mind is if you only used one keyboard for "full functionality" and the other simply as a generic MIDI controller. I am not sure if uninstalling the drivers from the other will work, but is a quick test of it being class compliant (i.e., uninstall their drivers and see if the keys work without any M-Audio drivers loaded). Bear in mind that the Ozone is very old (c. 1998), so will not reflect apples-to-apples with what you own at all. Obviously this is not the preferred route, but something you could check if desired.

Have you already tried uninstall M-Audio drivers for one/both keyboards?
 
They both should be class-compliant, "multiple units" should be no problem for MS drivers (in that respect the replay from M-audio sounds strange).
 
If that still does not work and you are familiar with computers, you can try to check properties for the devices in the device manager to find similarities. At least for MS drivers, there must be something which clash.

Probably asked and answered, but are you using usb2 or 3?

I believe you had mentioned that Windows see both controller, and it is within Sonar that you can only see one or the other.
 
What do music applications running stand-alone outside of Sonar see?  Can both controllers be enabled for use in on or more of these applications?  (Dim Pro, Rapture, etc).
 
Bob Bone