Hi Guys, had this very same issue. I am not sure my symptoms match your's, but here's mine. Basically air command, double tapping on the screen does not fire up the Action Memo app, which is supposed to in a normally functioning device.
First of all make sure you don't delete/free ALL your action memo instances in Titanium Backup. There's quite a few, so make sure they are not frozen.
Second, check to see if you have the xposed framework installed. If it is installed, un-install it and reboot. See if action memo works via Air command.
If Action Memo works after that, you can reinstall xposed framework. This is how I got mine working again. Hope it helps