I am using the same keyboard for years now and I never had a problem with it … Although I am using it through the USB connection (I don’t have a MIDI-Port on my PC). I would suggest using it on USB, straight into your PC (don’t use a hub) and get the latest drivers from the m-audio page (altough they are very old now).
this won’t help you much, but on a funny sidenote : I finally got my new mainboard yesterday, assembled my PC and reconnected all the cables. All of a sudden my midi-keyboard started working after a few minutes, every time in every host. The crazy solution for that was to connect the keyboard not directly to the PC but to an USB-Hub instead. Really strange.
The reason might be, that it didn’t get enough power to work reliable. I’ve experienced this with my 2,5" external HDD too, which worked fine on my active HUB (one with a power supply) but only sporadic on my mainboard connectors. Noticed also, that it can be dependent on the number of USB devices plugged into the mainboard at the same time.