Olimexino/MapleRET6 setInterval problem

When running the toggle LED from the Quickstart page the LED does not blink steadily.
It appears that there may be multiple calls to the setInterval callback function, toggle().
The shorter the interval the more noticeable the erratic blinking.

The boards are running off a battery with the console on serial1.

This happens with v1.72 .
with v1.71 I get no response from the boards
however with v1.70 this works as expected (steady blink).

function toggle() {
 on = !on;
 digitalWrite(LED1, on);
}

var interval = setInterval(toggle, 200);