Hello, I also see this more often. It usually happens when you create a file in millimetres and then switch to pixels and back again in between. I think it's a calculation error with the Intel processors on Macs.
My tip: Just ignore it. As far as I have noticed, it has no effect on the file.
- j.
P. S. Adobe could round the numbers, then you wouldn't see it. In Javascript there is this command after all:
function fUnit(pUnit1,pUnit2,pValue){ // convert units like mm to px
var vValue = new UnitValue (pValue, pUnit1);
return vValue.as(pUnit2);
} // end of function
and then there are no annoying decimal places.