Based on some Barnstormer photos, it would appear you have the outback gear.  I am not completely sure which issue you are describing.  I'll take a stab at a few possibilities. Relative to rigidity, the outback gear has some inherent drawbacks simply due to geometry.  The moment arm on the the actuator when compared to the increased length of the door is problematic. Tolerances in joints and simple flexing of components leads to the doors visibly shaking when extended on the ground with the engine running.

DoorShake.wmv  (white door is the original)

(http://www.n91cz.com/Outback-Gear/DoorShake.wmv) 
You mention changing the hinge.  The original was prone to cracking near the actuation point.  The with the actuation arm attached beyond the hinge, a disproportionate load is applied to the very first link.  I first discovered cracking during instrument training several years ago.  The doors spend much more time hanging out in the breeze during instrument approaches that they do in the traffic pattern.  Extending the hinge forward, beyond the actuator, distributes the load across the hinge sections more evenly.  This solved the cracking issue.   

http://www.n91cz.com/misc/gear_hinge_small.JPG

The final rigidity solution stems from a redesign tackling a different issue.  In resolving the problem of the outback doors deforming under aerodynamic loads and the trailing edges subsequently being pulled down in flight, the inboard gear door was shortened to half the original length.  This restores a more favorable ratio between door length and moment arm of the actuator.  The shorter door is the one nearer the camera in the video above.

Hopefully this helps.  If not, please elaborate on the details of your observations.  I'm sure someone on the list will have a good solution.

 

Chris Zavatson

N91CZ

360std

www.N91CZ.com