Problem with the "when" attribute of Position. Bug ?

Hi

I'm using the "when" attribute of a position.getInfo() : (Moment) when GPS time stamp of fix

On the simulator, all if OK. But on my fenix 3 HR I get strange values :

Time.now().value() is about 1462385124 [04/05/2016, 20:05:24 (UTC+0200)] ==> OK

BUT

var info=Position.getInfo();
info.when.value() ==> 2147483647 [19/01/2038, 04:14:07 (UTC+0100)] ?????

This value seems to be constant....

Is this a bug ?

Thanks