You might want to do a little more research before switching to another meter, which can be both expensive and annoying. If you're not washing your hands thoroughly before every measurement, the inaccuracy of your meter might be caused by the fact that the it picks up on traces of glucose left on your skin. This will explain why the tests are inaccurate specifically when you measure after eating. If this is the case, getting a new meter is a waste of money and will not solve your problem. I would advise you to try and wash your hands thoroughly before measuring and see if it solves the problem. If not, then a new meter is probably the way to go.
Some meters are not all that accurate. This could be a problem with your meter.