Pete
I did not assign actions to both the "Press" and "Release", but I did do more investigation based upon your input. Holding down the button has no effect but if I assign the macro to "Press" it will turn off the autopilot (AP) but pressing again will not turn the AP back on. If I assign the macro to "Release" it will turn the AP on but pressing it again will not turn the AP back off.
Now this is what is very strange - the button I am presently referring to is number 26 on the Throttle (Autopilot Engage/Disengage). If I assign this macro to "Press" on button 21 (L/G WRN), it works perfectly - press it once it turns the AP on, press it again it turns the AP off. I turned off the joystick in FS9 to assure no other actions were tied to button 26, I completely remove FSUPIC, cleaned out the registry, deleted all FSUPIC files in the modules folder, re-installed FSUPIC, - it did not fix the problem. I also verified using the Target script editor that buttons 26 and 21 send exactly the same signals (1 on Press, 0 on release). Is there somewhere else I can look that might be storing old data for button 26? Tony