SC840- WINPC NC-START WORKING ALMOST OPPOSITE OF PARK POSITION.......??

I've been away few months and before everything was working ok.
Now, what is happening is the following: I open a file and I prepare the machine for park position in the center of the working space, parameters for start/end are on origin+toolkit, zero in file bottom left, then i start and the machine goes all the way down on the Y axis, basically the exact opposite of the real start point that i defined and start to work from there.....this is really crazy, it never happened before, what could be the reason for this strange behaviour?
is a software problem or mechanical?

another strange thing is that when i try the reference point, i get an error message: error reference switch active.....??