MIDI keyboard stops working after a few minutes

hi, my first post here. As in the topic, I seem to have a problem with my old MK-225C Evolution keyboard,now M-Audio I suppose. Well, once I start Cubase (6.05) it works as normal for a few minutes and then just stops working-no midi activity at all. Same thing in Reaper so it must be something wrong with the system. I now connect it via USB. I’m on a sony vaio laptop, Win 7 64 bit, cubase 32 bit. I managed to find and download an updated driver from m-audio website but it hasn’t improved the situation. Now im using the laptop’s soundcard-I’m in the process of building up a new system after a few years of inactivity and will be getting an m-audio fast track ultra with proper midi in/out so will use that for my keyboard.
In the meantime, I’d like to be able to use the usb port if that’s possible.
Any ideas will be much appreciated

Strange, the only thing that springs to mind is that Windows disconnects the USB connection for power saving or something like that. Have a look through the activated power scheme maybe? It’s just a guess though.

Look into Emulated MIDI Ports, see sig.

I’ve checked windows power scheme as recommended and everything looks grand… I’ve also had a look at the midi section in the device setup and the midi ports seem to be active as normal. Or maybe I haven’t looked in the right place…
I’d be grateful for some more ideas.