Unexplained pauses

Hello,

Espruino looks like a great tool; however, I am having some difficulties.

I am using an HYSTM32_24.

I am using Espruino Web IDE. Connection to the board is fine, and it does operate some code.
Occasionally codes will not run and the board will not respond, requiring a reset.

Please could you explain why this code would work:

LCD.clear();
LCD.setColor(0, 0, 0.0);
LCD.fillRect(0, 0, 320, 240);
LCD.setFontBitmap();
LCD.setColor(0, 1, 0);
setTimeout(function() {
  LCD.drawString("> Line 1", 1, 10);
  LCD.drawString("> Line 2", 1, 30);
  }, 50);

but this code would cause it to pause?

LCD.clear();
LCD.setColor(0, 0, 0.0);
LCD.fillRect(0, 0, 320, 240);
LCD.setFontBitmap();
LCD.setColor(0, 1, 0);
setTimeout(function() {
  LCD.drawString("> Line 1", 1, 10);
  LCD.drawString("> Line 2", 1, 30);
  LCD.drawString("> Line 3", 1, 50);
  }, 50);

I am struggling to get three lines written one after the other!

Many thanks,

Harry