RC3000 cannot return to the base smoothly

Mine was doing the same thing.  Turned out to be dust that had gathered inside preventing the electric eyes (ir sensors) from work well.  Carefully using some lock ring pliers turn the three grey fasteners 90 degrees counter clockwise.  Then lift off the yellow top cover.  Using an air hose or soft brush clean the sensors sticking up from the circuit board.  Be careful not to bend the out ones has they are not hard mounted.  The also clean the inside of the IR windows on the yellow top cover.  While your at it take the time to blow out all the dust from the unit.  You should remove the inner screen prior to using compressed air so you can blow out the vac fan itself.  About every six months I do this or when it starts to act weird.  You should blow of all sensors on the base unit also.
Keith

CHECK TO BE SURE THE RUBBER SWEEP BEHIND THE BRUSH IS COMPLETLY INTACK & BE SURE ALL OTHER BOTTOM PARTS ARE IN CORRECT POSITION ROBERT K