2005 Honda VT750C

THIS HAS EXISTED SINCE NEW. THE TRANSMISSION DURING ACCELERATION AND JUST AFTER SHIFTING TO A HIGHER GEAR WILL RELEASE, REV IN A FALSE NEUTRAL AND JUMP BACK INTO GEAR, MOST TIMES TO THE NEXT LOWER GEAR. THIS MOSTLY HAPPENS BETWEEN THIRD AND FOURTH GEAR WHEN ACCELERATING HARD BUT HAS HAPPENED GOING FROM FOURTH TO FIFTH. THIS CAUSES THE BACK WHEEL TO LOCK UP AND SKID TILL RPM MATCHES WITH WHEEL TRACTION. HONDA FIRST ADJUSTED THE CLUTCH ON THE HANDLEBARS, DIDN'T WORK. TWO WEEKS LATER THEY HAD IT FOR TWO WEEKS AND CHANGED OUT THE ENTIRE SHIFTING LINKAGE BUT AFTER ABOUT 70 MILES THE SAME PROBLEM RECURRED THREE TIMES AN ALWAYS GOING FROM THIRD TO FOURTH. IT WAS BACK AT HONDA (HOUSE OF POWER, PALM BAY, FL) AGAIN THIS WEEK AND THEY TOOK IT FOR A FIVE MINUTE RIDE AND SAID THEY COULD NOT DUPLICATE THE PROBLEM. I HAD EXPLAINED THE INTERMITTENT PROBLEM AND THAT IT HAD HAPPENED ACROSS MILES OF DRIVING. IT ALSO SOMETIMES REVS A LITTLE LIKE THE CLUTCH IS SLIPPING. THEIR ANSWER IS SINCE THEY COULD NOT DUPLICATE THE PROBLEM THEY CAN DO NOTHING FOR ME. *NM.....AK