A few things:
does hardware manager show that is now has 1.01 firmware version on the MyDMX 3 dongle?
Make sure to close the hardware manager before launching the MyDMX 3 program, the driver shouldn't be split between the two programs and the MyDMX 3 programs need priority to the device. I assume you are using the June release of MyDMX 3, but are you using it on Windows or Mac and which release of either OS?