I have the 7.5 volt boards (came without buffer boards) Only have an issue in the winter. We have a hot air system. It appears that the dryer it is more static charges in the air and more likely that boards will freeze color wise while playing. Sometimes it will fix itself during a game otherwise a reboot is needed. I have replaced several boards with the newer boards with buffer but still have issues when the heat is blasting.
No issues at all during the warmer months, and have not had a board fail altogether.