Autopilot cutting out

Gentlemen;The autopilot sometimes will not engage, and it sometimes disengages while in flight.I know that the controls must be completely neutral, and the plane in trim, for the AP to engageupon pressing the CMD button.I have done the following:1. Calibrated my Logitech Joy Stick (Extreme 30 Pro).2. Lowered the sensitivity level for the Joy Stick.3. Turned OFF the realistic engagement option (FMC-Menu-setup-Option-Equipment).4. In FSUIPC set up module in the Misc page checked boxes to control spike elimination for rudder, elevator and aileron.5. While in flight disabled the Joy Stick and tried to engage CMD with no success, indicating that the cause was not a signal by the Joy Stick that it was not in neutral.6. I checked to confirm that the IRS switch was in the CENTER POSITION.I noted that in one flight, I was able to engage the AP after reaching a 1,000 ft flight levelAll went well, until I used the HAT BUTTONS on my Joy Stick to change the eye level view.The CMD button green light went out, and I was never able to re-engage the AP.I also read in the PMDG introduction manual that "...If no IRS unit is at least in ATT mode, CMD will disconnect andNEVER REENGAGE regardless of the IRS XFER switch." Does this mean that after alignment, the RIGHT IRSswitch must be in ATT mode rather than NAV? I tried this, but the Co-Pilot displays go out. What does thisquote from PMDG mean???? It seems that the AP is so sensitive, that once engaged, I need to keep my hands off the Joy Stick. What am I missing? What have I failed to do? Any help will be appreciated since this is very frustrating.Thanks,Stanner