It's not gonna get better until ya stop!!
   A few months ago I jumped from my saffire pro 40 interface to a presonus 24.4.2 board (has no midi I/O at all), and I ended up getting a faderport as well.  I got it mostly for the simple transport controls and maybe some automation/fader riding....     it was a monstrous PITA to get it set up for sonar, It was basically plug in and play with presonus's studio one though,   but after a week of messing with it, I got it working great.   Then I needed some Midi I/O so I went and picked up a cheap little midisport 1x1 usb midi thingamajig...  I hooked it up and it worked!  but it took out my faderport for Sonar. DAMNIT!   I haven't even attempted getting it back working yet because I am ready to throw it across the room!!     Is there a simple transport controller I can add to my little system that plays nice with sonar?  Just a RWD, Stop,Play, Rec.  buttons?    
  It is weird how both companies seem reluctant to offer useful support for these issues....  Like Presonus wants you to give up and just use their daw, and Cake is ticked that they don't have a similar controller that can beat it for the $130 price-point or something.

Chuck, I've had it happen a couple times. Try reinstalling the faderport drivers. That usually does the trick. Also, double check your settings to make sure that channel aftertouch is still enabled. Oh, and make sure you still have faderport in and out selected in the control surface prefs.

Seen something similar here, and heard enough other references to it I suspect a pattern.
 
Best I've come up with so far is Sonar doesn't play well w multiple MIDI/USB devices. MIDI via MIDI port pkus one MIDI/USB, no prob. More than one MIDI/USB device leads me to both 'working properly' in Device Manager, but only one of the two visible in Sonar.
 
Uninstalled both, and reinstalled one to recover, haven't attempted a second try for both yet, will update.
 
FWIW, I also have one (unused electrically) MIDI port on a Firewire interface, but no clue if thats significant.
 
 

Double. 
 

Sonar sometimes loses the Faderport and you have to make sure the settings in Sonar are correct.

I use it like you want to in Sonar 8.5 and it's great.

I just followed the 'how to install' posts from google but it was for 8.5 and not the X series.

Jay Tee 4303
Best I've come up with so far is Sonar doesn't play well w multiple MIDI/USB devices. MIDI via MIDI port pkus one MIDI/USB, no prob. More than one MIDI/USB device leads me to both 'working properly' in Device Manager, but only one of the two visible in Sonar.
 

I wouldn't phrase it quite as generic ... I'm running several USB/MIDI devices (VS700 + OctaCapture + A-Pro 800 + 2 BCFs + FCB1010 MIDI floorboard) successfully in my current set-up for 1 1/2 yrs without any of these problems ... I always switch all of them on in the same order (even if I don't use all of them in the session) ...
 
I'd suspect the faderport driver being a troublemaker, not Sonar ...

Oh I know it's not really Sonar's issue.  It is the fact that presonus doesn't care much about fixing issues between their hardware and a competing DAW.   I have my Faderport unplugged.  Not using it right now.  I lack the time for the headaches is going to take to keep it up and running.

 It is the fact that presonus doesn't care much about fixing issues between their hardware

 
It's a product that they're milking. It's likely (but I can't be sure) they didn't even write the driver, but contracted out.
 
I'm sure the later builds of faderport are fine, but I've got one of the ones with the faulty pan control. I've got the latest firmware - and I went so far as to use DeOxit in the case it might be dirty. No such luck, though. Surely, a faulty encoder - and since it's so freakin'  obvious, it raises a lot of questions. Don't they test their products during production? When they identify a production issue, do they rectify it for those examples that made it out the door?

This is a new unit, My wife picked one up for me for Christmas just a couple months ago.   When it works, it works fine I guess.  It just keeps going out. 

Leadfoot
Chuck, I've had it happen a couple times. Try reinstalling the faderport drivers. That usually does the trick. Also, double check your settings to make sure that channel aftertouch is still enabled. Oh, and make sure you still have faderport in and out selected in the control surface prefs.

Leadfoot,
 Did you completely uninstall and then start over or what?   I pulled out and deleted the dll's in C:program files, cakewalk, shared surfaces, then reinstalled, re-updated the firmware and I got the fader back & pan knob back but no transport controls, track switching, undo, arm, etc.  at all. 
Works fine in Studio one so I know it's an issue with it and sonar.