@elovalvo - gogol is right, people can't expect us to support clone devices, we just don't have the resources when people don't buy from us - especially in your case where both of your devices come form other companies and instead of creating their own software ITeadstudio is referring you to ours and their board is not properly made.
But to answer your question, as you are welcome to ask any question you want on our general arduino boards, just not our Digispark Support boards - those are for Digistump official products only -
The reason PB5 doesn't work is the itead didn't set the fuse bit on the attiny85 chip to disable the reset pin and make it an i/o pin - so instead of an i/o pin it is the reset which is why it puts the chip into resetting mode each time you connect it. Try a Digispark - they come ready to go and have a nunchuck shield as well.