Error when saving to flash

I had some similar issues here http://forum.espruino.com/conversations/297205/

Have looked at it again and have a 100% reproduction procedure:

1. Setup WebIDE:

• Reset before send [x] enabled
  
• Save on send [yes, even after reset]
  
  

2. copy into code pane (RHS) and click [^Send]

setInterval(()=>{
  digitalPulse(LED1, 1, 100);
}, 500 );

Left console shows:

[LOGO]
1v90.5 Copyright 2016 G.Williams
>Erasing Flash.....
Writing...
Compressed 32000 bytes to 66
Checking...
Done!
=undefined
Loading 66 bytes from flash...

Result: red LED is flashing, dump shows this:

>dump()
setInterval(function (undefined) {digitalPulse(LED1, 1, 100);}, 500);
// Code saved with E.setBootCode
setInterval(()=>{
  digitalPulse(LED1, 1, 100);
}, 500 );
=undefined

3. try reset(), but no effect: code is still there, LED is flashing

>reset()
=undefined
[LOGO]
 1v90.5 Copyright 2016 G.Williams
>dump()
setInterval(function (undefined) {digitalPulse(LED1, 1, 100);}, 500);
digitalWrite(D5, 1);
// Code saved with E.setBootCode
setInterval(()=>{
  digitalPulse(LED1, 1, 100);
}, 500 );
=undefined

4. change code on the RHS pane to something trivial and click [^Send] again

var x;

Result some death-loop with corrupt data:

>Erasing Flash.....
Writing...
Compressed 32000 bytes to 15
Checking...
Done!
Loading 15 bytes from flash...
Uncaught SyntaxError: Got ?[255] expected EOF
 at line 1 col 1
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ
^
in function called from system
>
=undefined
Uncaught SyntaxError: Got ?[255] expected EOF
 at line 1 col 1
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ

(tried on two different pucks now)
Maybe someone else can test and confirm this.