strange errors/behaviours on "send to Espruino"

I'm more and more running into strange problems sending code to Espruino.
Main part of my app is a module for TFT Display and Charting.
Problems I found are strange errormesssages or even stop/crashes.
2 easy to follow examples are, problems seem to appear in large sources(900 block used) only.

• in a module 2 similiar command crash the execution

  x = Math.round(x); //works fine
  

  x = Math.round(x);  //crashes with strange errormessage
  y = Math.round(y);  // replacing this by a 2nd x =Math.round(x) also crashed
  

• 2nd problem is a simple definition of an object which stops everything if writing in 2 lines

  wnds = [{left:50,top:100,right:150,bottom:200},{left:0,top:200,right:239,bottom:319}]; //this works
  

  wnds = [{left:50,top:100,right:150,bottom:200},
        {left:0,top:200,right:239,bottom:319}]; // this one stops without any message
  

Other strange behaviour could not be located (yet), I got errors on commented code to give an example. Uncommenting these lines moved the error message to another line, etc. etc.

I've been out of business due to a surgery for some weeks now, so I cannot give more information for when problems started.