Summit Induction top and Green-Pan ceramic not working

I have a new Summit SINC1110 induction cooktop and purchased three of your green-pan ceramic pieces. The small 8" skillet does not work at all, the 10" works if I rotate it round on the cooktop till it works, and the 2 qt sauce pan works the same, only in certain positions on the cooktop. The pots and pans that came with the cooktop (cheap and not ceramic) work in every position and every time they are set on the cooktop. Do you know what might be the problem?