Only explanation then for me seems to be that reset output driver of DS1232 has been damaged with experimenting.

Micro has this pull-down resistor inside, which is able to force low state at output of DS1232, even if output low driver transistor of DS1232 is damaged. So, when DS1232 is connected to micro low state is ok, but if disconnected to micro damaged output low driver transistor of DS1232 cannot pull the output down.

Kai