Helo
I've just recently started using Mach3 software with my cnc machine so this may be a very simple thing but i am lost at the moment

When i stop the machine during a session i write down the current g-code line so i can start from there tomorrow. After closing the program and turning it on again,i load the g-code and input the line form yesterday. I send the machine to my pre-set zeros, and here's the problem, they do not mach the ones form yesterday! Sometimes they are off by 1cm some times nowhere near it!