There seems to be a bit of controversy about not using all the grounds.I REMOVED THE 5V AND GROUND FROM THE ESCS
OK -SO YOURE SUGGESTING THAT I -JUST USE ONLY THE SIGNAL WIRES FROM THE ESCS -THEN USE THE UBEC TO POWER THE BOARD -There seems to be a bit of controversy about not using all the grounds.
What ESCs are you using and what is the rating their BECs can supply? Maybe it's just a matter of the BEC being pushed past it's limit.
An inexpensive UBEC may be a solution, effectively by passing the ESC completely.
http://www.banggood.com/Hobbywing-3A-UBEC-5V-6V-Switch-Mode-BEC-For-RC-Models-p-915037.html
OK - REATTACHING THE GROUNDS NOW - THXI'd always use all the grounds.