Is it consistently the same buttons that cause the detaches? If there's a wiring issue that's causing a short from power to ground, it could cause a detach. As you said, it could also be a power issue. If you have a multimeter, you can take the VINT Hub out of its enclosure and measure the voltage between the USB power and USB ground. If it dips below 4 volts when the detach happens, it's almost certainly a power issue.
You can also enable logging
, which will often provide a reason for the detach.