v2.04 Causes Resets

I just tried another one marked 'AI Thinker' and that seems to work ok.

>require('ESP8266').getState()    
={ 
  sdkVersion: "2.2.1(6ab97e9)", 
  cpuFrequency: 160, freeHeap: 11144, maxCon: 10, 
  flashMap: "4MB:1024/1024", 
  flashKB: 4096, 
  flashChip: "0xe0 0x4016"
 }

This is a 'doit esp8266' board which is giving me trouble (tried 2v00, 2v04 and now running the master build). Same results - resets on connection (when flashed with dio, doesn't connect when flashed with qio):

>require('ESP8266').getState()
={ 
  sdkVersion: "2.2.1(6ab97e9)", 
  cpuFrequency: 160, freeHeap: 13296, maxCon: 10, 
  flashMap: "4MB:1024/1024", 
  flashKB: 4096, 
  flashChip: "0xc8 0x4016"
 }
>process.env
={ 
  VERSION: "2v04", 
  GIT_COMMIT: "1c3547a", 
  BOARD: "ESP8266_4MB", 
  FLASH: 0, RAM: 81920, 
  SERIAL: "5ccf7fb8-e75e", 
  CONSOLE: "Serial1", 
  MODULES: "Flash,Storage,hea" ... "r,crypto,neopixel", 
  EXPTR: 1073643636 }