This is clearly a design fault of the U24. They should have put a circuit inside to clean the power via usb and/or add the possibility to connect the U24 to an dedicated external power supply.
I tried an external USB-hub with it's own external power supply. Unfortunately the U24 isn't recognized by the computer when connected via the hub but maybe this is just a matter of reinstalling the U24 drivers.
I am thinking now of modificating the U24 to make it work with an external power supply. The easiest way is probably to cut the USB cable in two and connect pins 1 and 4 of the part which leads to the U24 to an external power supply.
I tried an external USB-hub with it's own external power supply. Unfortunately the U24 isn't recognized by the computer when connected via the hub but maybe this is just a matter of reinstalling the U24 drivers.
I am thinking now of modificating the U24 to make it work with an external power supply. The easiest way is probably to cut the USB cable in two and connect pins 1 and 4 of the part which leads to the U24 to an external power supply.