Personally I'd think about updating the firmware on your ESP8266. I haven't come across version 0.21 before and it may behave differently - 0.25 (linked off the ESP8266 page) is the one that we've been developing/testing with...
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Personally I'd think about updating the firmware on your ESP8266. I haven't come across version 0.21 before and it may behave differently - 0.25 (linked off the ESP8266 page) is the one that we've been developing/testing with...