Error when saving to flash

Next time it happens, please could you do:

for (var i=(120-3)*4096;i<120*4096;i+=32) {
  var s = i.toString(16);
  for (var x=0;x<32;x+=4)
    s+=" "+("00000000"+peek32(i+x).toString(16)).substr(-8);
  console.log(s);
}

And post up what it reports?

That'll dump all the contents of the saved code area (which will probably take 30 seconds or so), but it should help me reproduce what's happening.