Transmission Slip Out Of Gear problems of the 1996 BMW Z3

1996 BMW Z3. The consumer states the vehicle has an incorrectly machined guide sleeve in the manual transmission. This causes the transmission to jump out of gear without any warning. The vehicle has not been taken to the dealership, but he has contacted the manufacturer about the problem. The manufacturer states there is no recall. The problem started on may 23, 2001. There has been nothing done to correct the problem. The problem is intermittent, and occurs only in first gear.