I got my tablet for a week now. Came with the v1 firmware. It used to crash randomly every 5 to 15 minutes. Everything freeze, and i must force power off, by holding power button. Can happen with any app. Kiledl all the chineese bloatware, no change I tried cache/factory reset, no change. I updated firware to v4, and it now crash less frequently, maybe once every 30min. Any hint on what i should do? Is it a defective unit?