Flymo 270 fixing pins

*I have just purchased a Flymo 270 lawnmower. This is the 5th or 6th Flymo I have Had over the last 50 yrs.and have never had any problems with other than the normal things caused by wear and tear. This new one I have been unable to give a test as the plastic pis which hold the handle onto the body of the machine keep falling out after only a matter of a few seconds. Has anyone else had this problem? As an ex design engineer I think these pins are inadequate for the purpose.