I believe it isn't necessary to reinstall fsuipc. When autothrottle [A/T] is engaged, the throttle levers movement is normal, like in real planes, "...going forward for a few then back down then up, etc...".

See http://www.wisegeek.com/what-is-an-autothrottle.htm (last paragraph)

"...this device controls the amount of thrust an aircraft's engines develop by increasing or decreasing their fuel flow. In some cases, the system will also physically move the throttle levers in the cockpit as is the case with Boeing and several other aircraft types. In other aircraft such as Airbus products, the throttle levers remain static even if thrust is being manipulated by the autothrottle."

Pinatubo.